Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Seismic Analysis of Cable-Stayed Bridges in the Frequency Domain Using Nonlinear Dynamic Analysis: Effects of Sequential Cable Failure Seismic Analysis of Cable-Stayed Bridges in the Frequency Domain Using Nonlinear Dynamic Analysis: Effects of Sequential Cable Failure 3 24 732510 FA Mahdi Yazdani Department of civil engineering, Arak university 0000-0001-8574-9667 Davood Farahani Faculty of Civil Engineering, Arak University Journal Article 2025 10 01 Practical experience from bridge construction has shown that partial failures—such as cable ruptures in cable-stayed bridges, which are critical and costly—are almost inevitable during construction and even throughout service life. Considering that many of these bridges are located in seismically active regions and must remain operational after earthquakes, this study investigates the influence of sequential cable failures on the seismic capacity of cable-stayed bridges in the frequency domain. The Bill Emerson Memorial Bridge was selected as a case study and modeled in OpenSees. After validation, scenarios of defective cable ruptures were considered, and the structure was subjected to nonlinear dynamic analyses under different intensities of the Superstition Hills earthquake. Dynamic responses—including deck displacement, velocity, and acceleration at mid-span in all three directions and pylon-top displacement, velocity, and acceleration in longitudinal and transverse directions—were recorded. Fourier Transform analysis was then applied to extract frequency-domain responses, and critical spectral peaks were identified using power spectral density analysis and compared with the fundamental frequencies of the bridge. The results indicate that rupture of two cables does not diminish the seismic capacity of the bridge; however, rupture of three cables leads to reductions, accompanied by frequency-content shifts that generate spectral peaks close to the structural natural frequencies. Transfer-function analysis showed that the deck response in the transverse direction exhibits higher sensitivity than in other directions due to its wider effective bandwidth. This finding suggests that provisions related to the control and design of deck torsional stiffness should be addressed with precision in current standards. Practical experience from bridge construction has shown that partial failures—such as cable ruptures in cable-stayed bridges, which are critical and costly—are almost inevitable during construction and even throughout service life. Considering that many of these bridges are located in seismically active regions and must remain operational after earthquakes, this study investigates the influence of sequential cable failures on the seismic capacity of cable-stayed bridges in the frequency domain. The Bill Emerson Memorial Bridge was selected as a case study and modeled in OpenSees. After validation, scenarios of defective cable ruptures were considered, and the structure was subjected to nonlinear dynamic analyses under different intensities of the Superstition Hills earthquake. Dynamic responses—including deck displacement, velocity, and acceleration at mid-span in all three directions and pylon-top displacement, velocity, and acceleration in longitudinal and transverse directions—were recorded. Fourier Transform analysis was then applied to extract frequency-domain responses, and critical spectral peaks were identified using power spectral density analysis and compared with the fundamental frequencies of the bridge. The results indicate that rupture of two cables does not diminish the seismic capacity of the bridge; however, rupture of three cables leads to reductions, accompanied by frequency-content shifts that generate spectral peaks close to the structural natural frequencies. Transfer-function analysis showed that the deck response in the transverse direction exhibits higher sensitivity than in other directions due to its wider effective bandwidth. This finding suggests that provisions related to the control and design of deck torsional stiffness should be addressed with precision in current standards.

https://jvs.isav.ir/article_732510_a082859c98c2f749cdf6220fecf43005.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Morphological Development and Acoustic Analysis of Sound Hole Designs Across Oud Instrument Morphological Development and Acoustic Analysis of Sound Hole Designs Across Oud Instrument 25 49 734320 FA Mohammad Mahdi Karbasbaf Alumnus of the Department of Mechanical Engineering, Qazvin Islamic Azad University, Iran Ghazaleh Ezaan Faculty of Social Sciences, Shahid Beheshti University, Iran Journal Article 2025 10 27 This investigation employs both historical morphological analysis and controlled acoustic experimentation to evaluate the influence of sound hole configurations on the resonance characteristics of short-necked lute instruments. Through systematic comparison of single-aperture versus triple-aperture designs across geographically diverse instrument traditions, we demonstrate significant quantitative differences in acoustic output parameters. Experimental measurements reveal that the triple-hole configuration (Mode 3) produces 55.35% higher RMS amplitude values compared to the fully enclosed configuration (Mode 1), and approximately 25% higher compared to the single-hole configuration (Mode 2). These findings indicate substantial improvements in sustained resonance, perceived loudness, and overall acoustic energy output in multi-aperture designs. The morphological survey traces sound hole evolution across Middle Eastern, European, and East Asian lute traditions, revealing consistent trends toward increased aperture complexity in performance-oriented instruments. Our results provide empirical validation for historical design preferences while offering quantitative metrics for contemporary instrument optimization. The enhanced amplitude characteristics and extended resonance of triple-hole configurations demonstrate clear advantages for applications requiring wide dynamic range and sustained tonal projection, with implications for both historical instrument reconstruction and modern acoustic design principles. This investigation employs both historical morphological analysis and controlled acoustic experimentation to evaluate the influence of sound hole configurations on the resonance characteristics of short-necked lute instruments. Through systematic comparison of single-aperture versus triple-aperture designs across geographically diverse instrument traditions, we demonstrate significant quantitative differences in acoustic output parameters. Experimental measurements reveal that the triple-hole configuration (Mode 3) produces 55.35% higher RMS amplitude values compared to the fully enclosed configuration (Mode 1), and approximately 25% higher compared to the single-hole configuration (Mode 2). These findings indicate substantial improvements in sustained resonance, perceived loudness, and overall acoustic energy output in multi-aperture designs. The morphological survey traces sound hole evolution across Middle Eastern, European, and East Asian lute traditions, revealing consistent trends toward increased aperture complexity in performance-oriented instruments. Our results provide empirical validation for historical design preferences while offering quantitative metrics for contemporary instrument optimization. The enhanced amplitude characteristics and extended resonance of triple-hole configurations demonstrate clear advantages for applications requiring wide dynamic range and sustained tonal projection, with implications for both historical instrument reconstruction and modern acoustic design principles.

https://jvs.isav.ir/article_734320_b2a42d93d1ece9fd7f821b8d10f98f89.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Optimization of Tuned Mass Damper Parameters Using Metaheuristic Algorithms-Case study of a shear 10-story Frame Optimization of Tuned Mass Damper Parameters Using Metaheuristic Algorithms-Case study of a shear 10-story Frame 50 67 732651 FA Seyed Mehdi Zahrai School of Civil Engineering, University of Tehran 0000-0003-2759-2424 Habibollah Ahmadi School of Civil Engineering, University of Tehran Journal Article 2025 10 26 Tuned Mass Dampers (TMDs) are widely recognized as effective passive control mechanisms for mitigating structural vibrations induced by seismic events. A critical aspect of their design involves the precise calibration of TMD parameters, which remains a significant engineering challenge. This research systematically addresses this issue by leveraging advanced metaheuristic optimization techniques to determine optimal TMD configurations under earthquake excitation. Four nature-inspired optimization techniques, Biogeography Based Optimization (BBO), Artificial Bee Colony (ABC), Cultural Algorithm (CA), and Firefly Algorithm (FA) were implemented and compared by selecting their distinct exploration-exploitation balance capabilities. These metaheuristic algorithms were used to systematically determine optimal TMD parameters, with the specific objective of minimizing peak roof displacement during seismic events. Numerical simulations conducted on a benchmark 10-story building model reveal a significant enhancement in seismic performance. The proposed approach achieves an average reduction in inter-story drift of approximately 38%, alongside a 36.5% decrease in the maximum roof displacement. These results signify a marked improvement over those attainable through conventional TMD design methods reported in the existing literature. The outcome underscores the heightened efficacy of the presented metaheuristic-driven framework in dissipating seismic energy and controlling displacement demands, thereby demonstrating its potential for improving the resilience of structures against earthquakes. Tuned Mass Dampers (TMDs) are widely recognized as effective passive control mechanisms for mitigating structural vibrations induced by seismic events. A critical aspect of their design involves the precise calibration of TMD parameters, which remains a significant engineering challenge. This research systematically addresses this issue by leveraging advanced metaheuristic optimization techniques to determine optimal TMD configurations under earthquake excitation. Four nature-inspired optimization techniques, Biogeography Based Optimization (BBO), Artificial Bee Colony (ABC), Cultural Algorithm (CA), and Firefly Algorithm (FA) were implemented and compared by selecting their distinct exploration-exploitation balance capabilities. These metaheuristic algorithms were used to systematically determine optimal TMD parameters, with the specific objective of minimizing peak roof displacement during seismic events. Numerical simulations conducted on a benchmark 10-story building model reveal a significant enhancement in seismic performance. The proposed approach achieves an average reduction in inter-story drift of approximately 38%, alongside a 36.5% decrease in the maximum roof displacement. These results signify a marked improvement over those attainable through conventional TMD design methods reported in the existing literature. The outcome underscores the heightened efficacy of the presented metaheuristic-driven framework in dissipating seismic energy and controlling displacement demands, thereby demonstrating its potential for improving the resilience of structures against earthquakes.

https://jvs.isav.ir/article_732651_030dfe13acf90f8e3a0cd063cb668f9f.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Acoustic Properties and Application of Nanofibers in Sound-Absorbing Materials Acoustic Properties and Application of Nanofibers in Sound-Absorbing Materials 68 82 731612 FA Azam Talebian Department of Textile Engineering, Yi. C., Islamic Azad University, Tehran, Iran Sima Habibi Department of Textile Engineering, Yi. C., Islamic Azad University, Tehran, Iran 0000-0002-3080-1664 Atieh Ghajarieh Young Researchers and Elite Club, Department of Textile Engineering, Yi. C., Islamic Azad University, Tehran, Iran 0000-0002-5024-616X Journal Article 2025 09 12 In recent years, noise pollution has been recognized as a major environmental challenge, and its destructive biological and psychological effects on humans and other living organisms have been demonstrated. The use of sound‑absorbing materials as an efficient method for noise reduction holds a special place in acoustic engineering. Among these materials, textile nanofibers, due to features such as ultra‑fine diameter, high specific surface area, and large porosity, can effectively improve the acoustic properties of materials without increasing weight and thickness. This paper also examines the mechanisms of sound absorption by nanofibers, reviews recent advances in the design and optimization of nanofibrous structures, and surveys their novel applications in noise reduction. The review results indicate that designing these structures by controlling parameters such as polymer type, fiber geometry, porosity level, layer thickness, and the method of combining with nanoparticles plays a decisive role in optimizing sound‑absorption performance across different frequency ranges. These findings provide a prospect for designing advanced acoustic absorbers with targeted frequency performance suitable for urban and industrial environments. In recent years, noise pollution has been recognized as a major environmental challenge, and its destructive biological and psychological effects on humans and other living organisms have been demonstrated. The use of sound‑absorbing materials as an efficient method for noise reduction holds a special place in acoustic engineering. Among these materials, textile nanofibers, due to features such as ultra‑fine diameter, high specific surface area, and large porosity, can effectively improve the acoustic properties of materials without increasing weight and thickness. This paper also examines the mechanisms of sound absorption by nanofibers, reviews recent advances in the design and optimization of nanofibrous structures, and surveys their novel applications in noise reduction. The review results indicate that designing these structures by controlling parameters such as polymer type, fiber geometry, porosity level, layer thickness, and the method of combining with nanoparticles plays a decisive role in optimizing sound‑absorption performance across different frequency ranges. These findings provide a prospect for designing advanced acoustic absorbers with targeted frequency performance suitable for urban and industrial environments.

https://jvs.isav.ir/article_731612_f09c595d95fe042449b556fbbf2b2c79.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Predictive Control of the Milad Tower Using a Semi-Active Tuned Mass Damper (SATMD) Integrated with Magnetorheological Dampers Predictive Control of the Milad Tower Using a Semi-Active Tuned Mass Damper (SATMD) Integrated with Magnetorheological Dampers 83 110 731462 FA Sina Jafarpour School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran 0009-0009-4646-5683 Seyed Mehdi Zahrai School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran 0000-0003-2759-2424 Journal Article 2025 09 15 In this study, the seismic performance of the Milad Tower equipped with a semi-active tuned mass damper (TMD) was evaluated under scaled earthquake records and compared with two other cases: uncontrolled and passive TMD systems. For a more comprehensive assessment, eight performance indices, including peak values and root mean square (RMS) responses, were utilized. The earthquake records were scaled using a wavelet-based spectral matching method to accurately represent the seismic energy content within the critical period ranges of the structure, enabling a more realistic dynamic analysis. In the semi-active system, a magnetorheological (MR) fluid damper was employed as the damping element within the TMD. To model the nonlinear behavior of these dampers, artificial neural networks (ANNs) were used, offering faster response prediction compared to traditional parametric models. Additionally, a model predictive controller (MPC) was implemented to regulate the damping force of the MR dampers. By forecasting the structural response in future time steps, this algorithm enabled rapid and targeted reactions to seismic excitations. Numerical results demonstrated the effectiveness of the proposed semi-active system in reducing the seismic responses of the tower. Specifically, RMS values of displacement, velocity, and inter-story drift were reduced by approximately 30% compared to the uncontrolled case, while the passive system achieved around 15% reduction. RMS acceleration also decreased by more than 15% in the semi-active case, whereas the passive system showed only about 3% reduction. These findings highlight the potential of combining predictive control with variable damping to enhance the seismic resilience of tall structures. In this study, the seismic performance of the Milad Tower equipped with a semi-active tuned mass damper (TMD) was evaluated under scaled earthquake records and compared with two other cases: uncontrolled and passive TMD systems. For a more comprehensive assessment, eight performance indices, including peak values and root mean square (RMS) responses, were utilized. The earthquake records were scaled using a wavelet-based spectral matching method to accurately represent the seismic energy content within the critical period ranges of the structure, enabling a more realistic dynamic analysis. In the semi-active system, a magnetorheological (MR) fluid damper was employed as the damping element within the TMD. To model the nonlinear behavior of these dampers, artificial neural networks (ANNs) were used, offering faster response prediction compared to traditional parametric models. Additionally, a model predictive controller (MPC) was implemented to regulate the damping force of the MR dampers. By forecasting the structural response in future time steps, this algorithm enabled rapid and targeted reactions to seismic excitations. Numerical results demonstrated the effectiveness of the proposed semi-active system in reducing the seismic responses of the tower. Specifically, RMS values of displacement, velocity, and inter-story drift were reduced by approximately 30% compared to the uncontrolled case, while the passive system achieved around 15% reduction. RMS acceleration also decreased by more than 15% in the semi-active case, whereas the passive system showed only about 3% reduction. These findings highlight the potential of combining predictive control with variable damping to enhance the seismic resilience of tall structures.

https://jvs.isav.ir/article_731462_5867e25a2a5a53fd604591edd87097a4.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Comparative Analysis of Impact Sound Transmission in Traditional and Modern Ceilings: A Case Study of Selected Buildings at Islamic Art University of Tabriz Comparative Analysis of Impact Sound Transmission in Traditional and Modern Ceilings: A Case Study of Selected Buildings at Islamic Art University of Tabriz 111 127 734395 FA Mahya Pezeshki Islamic Art University of Tabriz 0009-0007-3994-5510 Abas Ghaffari Faculty of Architecture and Urban Planning, Islamic Art University of Tabriz, Tabriz, Iran Journal Article 2025 09 28 Environmental sound is one of the key factors influencing educational performance and human interaction, and its quality plays an important role in both learner comfort and the effectiveness of the learning process. The adaptive reuse of buildings can significantly alter acoustic parameters and spatial characteristics; therefore, suitable interventions are necessary to enhance indoor acoustic conditions. Structure-borne sound, generated by impacts on surfaces and transmitted through the structure, is among the main sources of noise transmission and may negatively affect educational environments.This study aimed to conduct a comparative analysis of the acoustic behavior of traditional and modern roofs in response to structure-borne sound. The selected case studies were roofs of buildings at the Islamic Art University of Tabriz, chosen due to their conversion from residential to educational functions and the subsequent need for acoustic assessment. Field measurements were performed using B&K equipment.The sound pressure level (SPL) of five roof types was measured as the primary parameter to assess their performance against structure-borne sound, identifying which roof type showed the highest sound transmission and thus the weakest acoustic resistance. Analysis of SPL graphs within the frequency range of 400–5000 Hz demonstrated an increasing trend for all five roofs. However, the highest SPL values were associated with the reinforced concrete joist-block roof containing polystyrene infill. The proposed intervention effectively reduced SPL to acceptable levels in all cases, confirming the efficiency of the method. Environmental sound is one of the key factors influencing educational performance and human interaction, and its quality plays an important role in both learner comfort and the effectiveness of the learning process. The adaptive reuse of buildings can significantly alter acoustic parameters and spatial characteristics; therefore, suitable interventions are necessary to enhance indoor acoustic conditions. Structure-borne sound, generated by impacts on surfaces and transmitted through the structure, is among the main sources of noise transmission and may negatively affect educational environments.This study aimed to conduct a comparative analysis of the acoustic behavior of traditional and modern roofs in response to structure-borne sound. The selected case studies were roofs of buildings at the Islamic Art University of Tabriz, chosen due to their conversion from residential to educational functions and the subsequent need for acoustic assessment. Field measurements were performed using B&K equipment.The sound pressure level (SPL) of five roof types was measured as the primary parameter to assess their performance against structure-borne sound, identifying which roof type showed the highest sound transmission and thus the weakest acoustic resistance. Analysis of SPL graphs within the frequency range of 400–5000 Hz demonstrated an increasing trend for all five roofs. However, the highest SPL values were associated with the reinforced concrete joist-block roof containing polystyrene infill. The proposed intervention effectively reduced SPL to acceptable levels in all cases, confirming the efficiency of the method.

https://jvs.isav.ir/article_734395_d4985ccb84d8aaeaab7f2ea7faac6b07.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 A study on Acoustic Properties In Iranian Geometric Ornaments A study on Acoustic Properties In Iranian Geometric Ornaments 128 162 734536 FA Mohammad Mahdi Karbasbaf Alumnus of The Department of Mechanical Engineering, Qazvin Islamic Azad University, Iran Ghazaleh Ezaan Faculty of Social Sciences, Shahid Beheshti University, Iran Journal Article 2025 11 16 Traditional Iranian architectural ornamentation has historically been evaluated primarily through aesthetic and cultural lenses, with limited empirical investigation into its functional acoustic properties. This research addresses this scholarly gap by conducting the first comprehensive quantitative analysis of how geometric ornamental systems, including Kar-bandi, Yazdi-bandi, and Muqarnas, influence sound behavior in enclosed architectural spaces. Through controlled experimental methodology employing multi-domed hemispheric elements that replicate fundamental Kaseh-sazi geometries, this study examines the acoustic conditioning effects of these traditional design elements. The investigation bridges historical architectural practice with contemporary acoustic science by demonstrating how master builders intuitively incorporated geometric patterns to achieve specific acoustic outcomes. Our findings reveal that these ornamental systems create measurable modifications in sound propagation, reflection patterns, and overall acoustic response, providing empirical validation of traditional Iranian acoustic design principles. The research employs mathematical modeling alongside experimental observation to quantify the acoustic impact of these geometric forms, establishing a scientific foundation for understanding the dual aesthetic-functional nature of Iranian architectural ornamentation. This work contributes to both historical architectural documentation and modern acoustic design practice, demonstrating the continued relevance of traditional building knowledge in contemporary applications. By documenting and validating these acoustic principles, the study preserves important cultural architectural wisdom while advancing the field of architectural acoustics through quantitative analysis of historically-informed design strategies. Traditional Iranian architectural ornamentation has historically been evaluated primarily through aesthetic and cultural lenses, with limited empirical investigation into its functional acoustic properties. This research addresses this scholarly gap by conducting the first comprehensive quantitative analysis of how geometric ornamental systems, including Kar-bandi, Yazdi-bandi, and Muqarnas, influence sound behavior in enclosed architectural spaces. Through controlled experimental methodology employing multi-domed hemispheric elements that replicate fundamental Kaseh-sazi geometries, this study examines the acoustic conditioning effects of these traditional design elements. The investigation bridges historical architectural practice with contemporary acoustic science by demonstrating how master builders intuitively incorporated geometric patterns to achieve specific acoustic outcomes. Our findings reveal that these ornamental systems create measurable modifications in sound propagation, reflection patterns, and overall acoustic response, providing empirical validation of traditional Iranian acoustic design principles. The research employs mathematical modeling alongside experimental observation to quantify the acoustic impact of these geometric forms, establishing a scientific foundation for understanding the dual aesthetic-functional nature of Iranian architectural ornamentation. This work contributes to both historical architectural documentation and modern acoustic design practice, demonstrating the continued relevance of traditional building knowledge in contemporary applications. By documenting and validating these acoustic principles, the study preserves important cultural architectural wisdom while advancing the field of architectural acoustics through quantitative analysis of historically-informed design strategies.

https://jvs.isav.ir/article_734536_35640a40588d430dc35b4905666c96a2.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Vibration analysis of functionally graded folded plate: A differential quadrature approach and first-order shear deformation theory Vibration analysis of functionally graded folded plate: A differential quadrature approach and first-order shear deformation theory 163 177 735762 FA Nima Mohandesi Department of Mechanical Engineering, Qom University of Technology Mostafa Talebitooti Department of Mechanical Engineering, Qom University of Technology, Qom, Iran Mohammad Fadaee Department of Mechanical Engineering, Qom University of Mechanical Engineering, Qom, Iran Journal Article 2025 06 04 This research investigates the vibration behavior of folded plates made of functionally graded materials (FGMs). FGMs, as an advanced material class, possess a heterogeneous structure with mechanical properties that continuously vary through the thickness. Folded plates are utilized in various industries due to their ease of manufacturing and low production cost. A novel application of these plates is in the design and construction of fifth-generation stealth fighter aircraft. In this study, the elastic moduli and density of the FGM folded plate were initially considered. Subsequently, using Hamilton's principle, the governing dynamic equations and boundary conditions for each layer of the folded plate were separately derived. By applying continuity conditions at the folded region, the governing equations, boundary conditions, and continuity equations were formulated in a unified manner. To analyze this equation set, a combined Levy-Ritz method was employed, and the natural frequencies of the FGM folded plate were calculated by solving the eigenvalue problem. For validation purposes, the FGM folded plate was modeled and analyzed in COMSOL simulation software (based on the finite element method). Comparison of the finite element results with those obtained from the combined Levy-Ritz method demonstrates the high accuracy of the mathematical modeling and analytical solution method presented in this research. This research investigates the vibration behavior of folded plates made of functionally graded materials (FGMs). FGMs, as an advanced material class, possess a heterogeneous structure with mechanical properties that continuously vary through the thickness. Folded plates are utilized in various industries due to their ease of manufacturing and low production cost. A novel application of these plates is in the design and construction of fifth-generation stealth fighter aircraft. In this study, the elastic moduli and density of the FGM folded plate were initially considered. Subsequently, using Hamilton's principle, the governing dynamic equations and boundary conditions for each layer of the folded plate were separately derived. By applying continuity conditions at the folded region, the governing equations, boundary conditions, and continuity equations were formulated in a unified manner. To analyze this equation set, a combined Levy-Ritz method was employed, and the natural frequencies of the FGM folded plate were calculated by solving the eigenvalue problem. For validation purposes, the FGM folded plate was modeled and analyzed in COMSOL simulation software (based on the finite element method). Comparison of the finite element results with those obtained from the combined Levy-Ritz method demonstrates the high accuracy of the mathematical modeling and analytical solution method presented in this research.

https://jvs.isav.ir/article_735762_83ddcb049b9a4bda4b8140c13246fe2a.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Modeling vehicle driving parameters to optimize vibrations of cargo types in different frequency ranges using machine learning Modeling vehicle driving parameters to optimize vibrations of cargo types in different frequency ranges using machine learning 178 199 733274 FA Salman Imanpour Ph.D. Student, Faculty of Engineering, Imam Hossein University, Tehran, Iran 0009-0004-1451-7518 Saeed Mahjoub Moghadasi Associate Professor, Faculty of Engineering, Imam Hossein University, Tehran, Iran Seyed Mohammad Modarres Researcher, Faculty of Engineering, Imam Hossein University, Tehran, Iran Journal Article 2025 09 30 Vehicle vibrations can significantly impact the health of the vehicle's cargo and its overall performance. This study investigates the effects of tire pressure, vehicle cargo weight, and driving speed on vehicle vibrations using both analytical and experimental methods, aiming to optimize vibration energy in different frequency ranges and determine optimal conditions for two specific types of cargo. By analyzing the interactions between these three factors, this research seeks to identify the main factors influencing vibrations and their potential combined effects, ultimately finding vibrationally optimal states for different cargo types. Vehicle speed, tire pressure, and cargo weight were systematically varied, vibrations were measured, and the impact of each variable and their interactions on vibration levels was assessed. Three factors (speed, tire pressure, and cargo weight) were tested at three levels with four repetitions, totaling 108 experiments. The results show that vehicle speed has the greatest effect. Tire pressure and cargo weight have much smaller effects compared to speed. Also, the vibration level is highest in the vertical direction and lowest in the longitudinal direction of the vehicle. Finally, optimal parameters were calculated for two types of cargo. This was done using both traditional methods and machine learning methods. Among the machine learning methods, the decision tree algorithm, as an interpretable method, has greater accuracy than the traditional method. The results of this research have many applications in UGV, especially tactical UGV that carry sensitive cargo. Vehicle vibrations can significantly impact the health of the vehicle's cargo and its overall performance. This study investigates the effects of tire pressure, vehicle cargo weight, and driving speed on vehicle vibrations using both analytical and experimental methods, aiming to optimize vibration energy in different frequency ranges and determine optimal conditions for two specific types of cargo. By analyzing the interactions between these three factors, this research seeks to identify the main factors influencing vibrations and their potential combined effects, ultimately finding vibrationally optimal states for different cargo types. Vehicle speed, tire pressure, and cargo weight were systematically varied, vibrations were measured, and the impact of each variable and their interactions on vibration levels was assessed. Three factors (speed, tire pressure, and cargo weight) were tested at three levels with four repetitions, totaling 108 experiments. The results show that vehicle speed has the greatest effect. Tire pressure and cargo weight have much smaller effects compared to speed. Also, the vibration level is highest in the vertical direction and lowest in the longitudinal direction of the vehicle. Finally, optimal parameters were calculated for two types of cargo. This was done using both traditional methods and machine learning methods. Among the machine learning methods, the decision tree algorithm, as an interpretable method, has greater accuracy than the traditional method. The results of this research have many applications in UGV, especially tactical UGV that carry sensitive cargo.

https://jvs.isav.ir/article_733274_4e5b410faf8d9732f897ac5c1d540489.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Vibration Analysis of Rotating Porous Conical Shells Using the Two-Dimensional Generalized Differential Quadrature Method Vibration Analysis of Rotating Porous Conical Shells Using the Two-Dimensional Generalized Differential Quadrature Method 200 217 736042 FA Ali Asghar Jafari Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran Seyed Amirmasoud Takmili Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran Journal Article 2025 11 22 This study investigates the vibrational behavior of a rotating conical shell composed of a functionally graded porous material. The governing equations for a relatively thick conical shell are derived based on the first-order shear deformation theory. These equations incorporate the effects of centrifugal forces induced by the shell's rotation, which result in an initial hoop tension strain energy. The partial differential equations are discretized into a set of algebraic equations using the two-dimensional generalized differential quadrature (2D-GDQ) method. The natural frequencies of the system are subsequently obtained by solving the resulting eigenvalue problem. Following the validation of the proposed mathematical model, the influence of various parameters—including rotational speed, boundary conditions, porosity material, and the cone's semi-vertex angle—on the forward and backward natural frequencies is examined. The results indicate that an increase in the porosity parameter leads to a reduction in the natural frequency. Conversely, the natural frequency values are found to increase with higher rotational speeds. This study investigates the vibrational behavior of a rotating conical shell composed of a functionally graded porous material. The governing equations for a relatively thick conical shell are derived based on the first-order shear deformation theory. These equations incorporate the effects of centrifugal forces induced by the shell's rotation, which result in an initial hoop tension strain energy. The partial differential equations are discretized into a set of algebraic equations using the two-dimensional generalized differential quadrature (2D-GDQ) method. The natural frequencies of the system are subsequently obtained by solving the resulting eigenvalue problem. Following the validation of the proposed mathematical model, the influence of various parameters—including rotational speed, boundary conditions, porosity material, and the cone's semi-vertex angle—on the forward and backward natural frequencies is examined. The results indicate that an increase in the porosity parameter leads to a reduction in the natural frequency. Conversely, the natural frequency values are found to increase with higher rotational speeds.

https://jvs.isav.ir/article_736042_0a14748367d75cbcec712c29cb2bc0c6.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Experimental identification of natural frequencies of a gas turbine blade using a non-contact microphone-based measurement method Experimental identification of natural frequencies of a gas turbine blade using a non-contact microphone-based measurement method 218 228 735305 FA Ali Rahi Shahid Beheshti Unv. ُSyed Ahmad Mortazavi Shahid Beheshti Unv. Abbas Rahi Faculty of Mechanical and Energy Engineering, Shahid Beheshti University, Tehran, Iran 0000-0002-7123-1741 Journal Article 2026 02 20 Identification of natural frequencies is one of the key tools for analyzing the dynamic behavior of gas and steam turbine blades and plays a critical role in power generation and aerospace industries. In lightweight and sensitive blades, the use of contact sensors such as accelerometers introduces additional mass and damping into the system, leading to increased errors in estimating natural frequencies. In this study, the natural frequencies of a turbine blade are measured using a non‑contact microphone‑based acoustic sensing method. The blade is suspended under free–free boundary conditions and excited by an impulse hammer, while the resulting vibration response is captured as an acoustic signal by a microphone. The signals are processed using a data acquisition system and the FFT algorithm to extract the natural frequencies. The experimental results are compared with finite‑element simulations performed in ANSYS. The data show that the proposed method can identify the blade’s natural frequencies with a relative error of less than 2%, and the corresponding phase transitions in the frequency response function confirm the validity of the non‑contact measurement approach. Identification of natural frequencies is one of the key tools for analyzing the dynamic behavior of gas and steam turbine blades and plays a critical role in power generation and aerospace industries. In lightweight and sensitive blades, the use of contact sensors such as accelerometers introduces additional mass and damping into the system, leading to increased errors in estimating natural frequencies. In this study, the natural frequencies of a turbine blade are measured using a non‑contact microphone‑based acoustic sensing method. The blade is suspended under free–free boundary conditions and excited by an impulse hammer, while the resulting vibration response is captured as an acoustic signal by a microphone. The signals are processed using a data acquisition system and the FFT algorithm to extract the natural frequencies. The experimental results are compared with finite‑element simulations performed in ANSYS. The data show that the proposed method can identify the blade’s natural frequencies with a relative error of less than 2%, and the corresponding phase transitions in the frequency response function confirm the validity of the non‑contact measurement approach.

https://jvs.isav.ir/article_735305_22072fc5b66b6c019eb004bd3457f267.pdf

Iranian Society of Acoustics and Vibration Journal of Vibration and Sound 2383-1839 14 28 2026 02 20 Analytical Modeling and Vibroacoustic Analysis of a Coupled Structural–Acoustic Rectangular Cavity with a Viscoelastic Flexible Plate Analytical Modeling and Vibroacoustic Analysis of a Coupled Structural–Acoustic Rectangular Cavity with a Viscoelastic Flexible Plate 229 248 735272 FA Vahid Khoramirad PhD student in Mechanical Engineering, Khajeh Nasir Toosi University of Technology Aliasghar Jafari Professor, Faculty of Mechanical Engineering, Khajeh Nasir Toosi University of Technology Journal Article 2026 01 03 This paper presents the analytical modeling and response analysis of a coupled structural-acoustic system comprising a rectangular enclosed acoustic cavity with a flexible wall and a viscoelastic layer. The system is modeled using the Rayleigh–Ritz method within the framework of structural-acoustic coupling under weak coupling conditions. The vibrational response of the flexible wall is calculated by incorporating viscoelastic damping effects, and the internal acoustic response is subsequently determined by solving the wave equation while accounting for structure–fluid interaction. To examine the influence of structural parameters and damping materials, the flexible wall thickness is varied at three levels (3, 5, and 7 mm), and the addition of a viscoelastic layer is investigated. Results indicate that wall thickness and viscoelastic properties significantly influence the vibration amplitude and internal sound pressure, effectively reducing both vibration and interior noise. The analytical results are validated against finite element simulations in ANSYS, showing good agreement and confirming the model's reliability for analyzing and designing noise and vibration reduction systems in engineering enclosures. The key novelty of this research lies in developing an analytical model that independently quantifies the contributions of plate bending stiffness and viscoelastic damping to acoustic response reduction across different frequency ranges. The model reveals that at low frequencies, the effect of plate thickness entirely dominates viscoelastic damping, whereas at high frequencies, a synergistic effect between the two is observed. This paper presents the analytical modeling and response analysis of a coupled structural-acoustic system comprising a rectangular enclosed acoustic cavity with a flexible wall and a viscoelastic layer. The system is modeled using the Rayleigh–Ritz method within the framework of structural-acoustic coupling under weak coupling conditions. The vibrational response of the flexible wall is calculated by incorporating viscoelastic damping effects, and the internal acoustic response is subsequently determined by solving the wave equation while accounting for structure–fluid interaction. To examine the influence of structural parameters and damping materials, the flexible wall thickness is varied at three levels (3, 5, and 7 mm), and the addition of a viscoelastic layer is investigated. Results indicate that wall thickness and viscoelastic properties significantly influence the vibration amplitude and internal sound pressure, effectively reducing both vibration and interior noise. The analytical results are validated against finite element simulations in ANSYS, showing good agreement and confirming the model's reliability for analyzing and designing noise and vibration reduction systems in engineering enclosures. The key novelty of this research lies in developing an analytical model that independently quantifies the contributions of plate bending stiffness and viscoelastic damping to acoustic response reduction across different frequency ranges. The model reveals that at low frequencies, the effect of plate thickness entirely dominates viscoelastic damping, whereas at high frequencies, a synergistic effect between the two is observed.

https://jvs.isav.ir/article_735272_2624a30ace14e759e6b5605cc88035ee.pdf