Shock and Vibration最新文献

{"title":"Multiobjective Optimization of Composite Material Seat Plate for Mortar Based on the Hybrid Surrogate Model","authors":"Fengfeng Wang, Chundong Xu, Lei Li","doi":"10.1155/2024/8387179","DOIUrl":"https://doi.org/10.1155/2024/8387179","url":null,"abstract":"As an important force transmission component of mortars, the seat plate affects some core indicators of mortars such as range, shooting accuracy, and maneuverability. In order to withstand huge impact loads, the seat plate was previously made of metal, which accounts for approximately 30%–45% of the total weight of the gun. The drawbacks of the heavy weight of the seat plate, which are not conducive to transportation and transfer, run counter to the current direction of the mortar’s lightweight development. The application of composite materials can greatly reduce the weight of the seat plate, but it exacerbates the contradiction between the mobility and combat effectiveness of mortars. In order to achieve the best match between mortar stability and maneuverability, a multiobjective optimization of composite material layers for seat plates is proposed, utilizing the designability of composite material layers. First, a fiber continuity model based on dropout sequence is adopted to solve the problems existing in the design of inherent continuity classes for composite layered fibers. Second, a hybrid surrogate model that considers the composite material seat plate quality, structural strength, shooting stability, shooting accuracy, and various working conditions is considered. Then, in order to improve the optimization efficiency and robustness of the algorithm, a multiobjective optimization algorithm based on the Chebyshev combination pattern is used to solve the mixed surrogate model. Finally, the optimization results are comprehensively evaluated against the optimization objectives. Research has shown that the method proposed in this article can effectively solve the time-consuming problem of multiobjective optimization, improve the accuracy of hybrid surrogate models, and meet the expected requirements of multiobjective optimization of composite material seat plates. While ensuring shooting stability, the weight of the seat plate is reduced by 18.43% compared to the metal seat plate, which has important application value for lightweight design of mortars.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"21 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Response of Offshore Wind Turbine with a New Monopile Foundation under Different Lateral and Seismic Loadings","authors":"Mehdi Ebadi-Jamkhaneh, Denise-Penelope N. Kontoni","doi":"10.1155/2024/2329389","DOIUrl":"https://doi.org/10.1155/2024/2329389","url":null,"abstract":"Using a monopile foundation due to a reliable and simple technology has a wide application in engineering structures. This paper investigates numerically the performance of an offshore wind turbine with a monopile foundation equipped with a restriction plate at a middle inside height of the monopile under the wind, wave, and seismic loadings. Different parameters, including wind velocity, wave period, wave height, soil characteristics, and combination of loadings, are considered in nonlinear finite element dynamic analyses. Results are given in terms of the distribution of displacement and bending moment over the turbine height and frequencies. The results reveal that by increasing the wind velocity, the responses of the tower increase, and the wind load acting on the hub has the most important effect on the turbine behavior rather than the wind load acting on the tower body. Furthermore, the values of maximum displacement and bending moment under wind and wave loading decrease with the increase of the shear strength of the soil, whereas the responses of the tower under earthquake loading increase. Generally, it is necessary to consider the effect of a combination of wind, wave, and earthquake loadings on the design of the turbine tower.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"21 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pole Allocation Applied to Two Buildings Connected by Joint Damper","authors":"Yoshiki Ikeda, Yuki Matsumoto","doi":"10.1155/2024/5363146","DOIUrl":"https://doi.org/10.1155/2024/5363146","url":null,"abstract":"For two adjacent buildings connected by a joint damper, an inverse problem is formulated based on the pole allocation method in control theory. The structural system is simplified as a two-degrees-of-freedom (2-DOF) lumped-mass damped shear model. The unified governing equation, which expresses the relationship between an assigned control target and the structural parameters for an earthquake-resistant building, seismically isolated building, or passively controlled building, is extended to structural control using a joint damper. The introduced equation automatically constrains the variations in the structural parameters under the assigned modal properties. The integration of the pole allocation method and fixed-point theory directly estimates the additional damping effect on the target buildings from the optimum capacity of the joint damper, which improves the trial-and-error steps at the preliminary design stage. The past fixed-point theories do not provide the additional damping effect but the optimum damping coefficient of the joint damper. The present study directly links the additional damping with the damping of the joint damper. Numerical examples are used to verify the theoretical integration using a 20-DOF building model wherein two 10-DOF models are connected by a joint damper between the top lumped masses.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"86 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139586463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shock Reduction Technique in Thin-Plate Structure Using Elastic Patches with Gradual Thickness Variations","authors":"Hyun-Su Park, Dae-Hyun Hwang, Jae-Hung Han","doi":"10.1155/2024/9243316","DOIUrl":"https://doi.org/10.1155/2024/9243316","url":null,"abstract":"Reducing structural shocks propagated as elastic waves in thin plate-like structures is of paramount importance in diverse engineering applications. In this study, a shock reduction method using elastic patches that deflect bending waves through wave refraction, while maintaining the structural stiffness and strength is presented. Elastic patches with gradual thickness variation were designed and thoroughly investigated both numerically and experimentally. Two types of triangular elastic patches, flat and pyramid-shaped, were utilized to refract and attenuate transient bending waves at different incident angles. All results from ray tracing, finite element analysis, and experiments consistently demonstrated the effective reduction of passing waves in areas behind the attached patches. Moreover, the influence of gradual thickness variation was thoroughly discussed. The proposed method provides a practical approach to mitigate transient shock responses in specific target areas across various structural applications without compromising structural stiffness and strength.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"4 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139560077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Wheel Wear and Wheel-Rail Dynamic Characteristics of High-Speed Trains under Braking Conditions","authors":"Rui Song, Chenxu Lu, Lixia Sun, Zhongkai Zhang, Dilai Chen, Gang Shen","doi":"10.1155/2024/9618500","DOIUrl":"https://doi.org/10.1155/2024/9618500","url":null,"abstract":"When high-speed trains operate under braking conditions, the wheel-rail interaction increases significantly, which can lead to more serious wear problems. To analyze the evolution of wheel wear and the dynamic characteristics of wheel-rail under braking conditions, this paper first carries out long-term monitoring of the service state of wheel-rail during the operation period. The study analyzed the matching characteristics of the measured wheel-rail profile and calibrated the wear model by using the collected data. The resulting wear prediction model was then used to examine the wheel wear characteristics under braking conditions. The research results indicate that during the operation period, the wheel experiences tread concave wear within a range of ±20 mm of the rolling circle, at a rate of approximately 0.05 mm per 10,000 km. Meanwhile, the rail experiences top surface wear at a natural rate of about 0.09 mm per year. Concave wear causes the contact point of the wheel-rail to appear in two zones, resulting in a sudden change of contact geometric parameters. The concave worn wheel and rail with a 60 N profile have better matching compared to the 60 rail profile. Increasing the braking torque and wheel-rail friction coefficient will significantly increase the wheel wear depth on straight sections. On small-radius curve sections, rail side lubrication can significantly reduce high rail side wheel flange wear. A worn concave wheel can lead to unfavorable wheel-rail contact geometry characteristics and increase low-frequency components in the vehicle’s lateral dynamic response.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"84 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139559880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Vibration Transmission Path in Packaging System and Design of Teaching Experiment","authors":"Meilin Gong, Cong Lin","doi":"10.1155/2024/5213904","DOIUrl":"https://doi.org/10.1155/2024/5213904","url":null,"abstract":"It is essential for realizing the most suitable product buffer packaging design to quantify the vibration transmission characteristics of the product packaging system. The experiment system for the vibration transmission path of protective packaging is designed in this paper. The practical system is used to analyze the vibration transfer path of the product packaging system and identify the critical transfer path. The concepts of the cushions’ contribution rate and the cushions’ weighted contribution rate are introduced. The product cushioning based on the weighted equal contribution rate of the cushions is proposed. It has been verified by experiments that the system can accurately identify the transfer path with the weighted contribution rate of the cushions as a reference for the design of product buffer packaging, which improves the utilization rate of buffer packaging materials and reduces the cost of packaging materials. The weighted equal contribution rates of buffer pads 1, 2, 3, and 4 are 40%, 27%, 22%, and 11%, respectively. For the needs of experiment teaching, the teaching content based on the protective packaging transfer path testing system is designed, which provides a reference for the practical education of the packaging specialty.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"46 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139515213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study and Seismic Response Evaluation of Chlorobutyl Rubber-Based Viscoelastic Dampers","authors":"Farnoosh Roshan-Tabari, Hamid Toopchi-Nezhad, Ghodratollah Hashemi-Motlagh","doi":"10.1155/2024/7198551","DOIUrl":"https://doi.org/10.1155/2024/7198551","url":null,"abstract":"Conventional viscoelastic devices often use high-damping elastomeric pads, typically made of patented formulations, that are bonded to steel plates. The response properties of these pads under cyclic shear deformations directly influence the load-deformation hysteretic response of the device. Chlorobutyl (CIIR) is a high-damping rubber commonly used in industrial applications. However, this study found that the damping properties of a typical CIIR rubber compound are insufficient for effective structural seismic mitigation at ambient temperatures above 0°C. The goal of this study was to develop a new composite of CIIR, referred to as modified CIIR, with improved damping properties and to compare its performance with that of the reference CIIR rubber. In the first phase of the experimental studies, the viscoelastic characteristics of the reference and modified CIIR rubber materials were evaluated using dynamic mechanical thermal analysis (DMTA) in tension mode. Prototype viscoelastic damper devices were then fabricated from both the reference and modified CIIR rubber materials and subjected to cyclic shear tests at room temperature and various loading frequencies. The results showed that the modified CIIR rubber exhibited significantly improved effective damping compared to the reference CIIR. The final component of this study involved investigating the seismic response of a 2D frame structure equipped with prototype dampers made from both reference and modified CIIR materials, using nonlinear time-history analyses. The analysis results indicated that the modified CIIR rubber can be effectively utilized in the seismic response mitigation of structures.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"146 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139496801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Influence of Missile Cabin on Fragment Velocity under Explosive Detonation Impact","authors":"Xin Li, Weili Wang, Zhengfeng Liang, Jun Dong, Jiaojiao Tang","doi":"10.1155/2024/3686948","DOIUrl":"https://doi.org/10.1155/2024/3686948","url":null,"abstract":"For the air-to-air missile warhead, there is a cabin with a certain thickness at a distance around the fragments. At present, the influence of missile cabin has not yet been taken into account in the study of fragment velocity. In this paper, based on the law of conservation of energy, the theoretical equation of fragment velocity considering the kinetic energy of cabin debris was deduced. Then, the rationality of the theoretical formula is validated through the static explosion experiments of two prototype warheads, one with a titanium alloy cabin and the other without any cabin. It was found that after the warhead is equipped with the cabin, part of the energy is consumed to drive the cabin debris, resulting in a decrease in fragment velocity, but the velocity of cabin debris was greater than that of fragment of warheads without any cabin. Besides, through numerical simulation, the driving process of fragments and cabin debris during explosive detonation loading of the warhead with the cabin was studied, which can be divided into six stages, and the error between numerical result and experimental value is not more than 4.8%. Finally, the variety regulation of fragment velocity and cabin debris velocity at different interval distances was further studied by numerical simulation. The results indicate that fragment velocity of warheads with cabin at different interval distances is basically the same, but cabin debris velocity decreases with the increase of interval distance. This conclusion can provide a reference for the structural design and fragment velocity evaluation of warheads with cabin.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139496799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on Numerical Simulation of Surrounding Rock Structure Safety of Urban Underwater Shield Tunnel: A Case in Chongqing","authors":"Zeng-Qiang Yang, Xiao-Ming You, Hui-Wu Jin","doi":"10.1155/2024/9285252","DOIUrl":"https://doi.org/10.1155/2024/9285252","url":null,"abstract":"Based on the engineering background of shield construction of a subway section in Chongqing, which needs to pass through a park and there is a lake inside this park, this paper adopts theoretical analysis methods and numerical simulation calculation methods to explore the distribution law of the seepage field and the characteristics of water pressure in lining segments during shield tunneling. The results show that, during the whole excavation of a double-track tunnel with EPB shield, the maximum vertical effective stress is about 4.24 MPa, which is located at the arch foot of the tunnel. The maximum effective stress in the horizontal direction is about 3.61 MPa, which is located on both side walls of the tunnel in the horizontal direction; after the left and right tunnels are excavated in sequence, a “double precipitation funnel-shaped” pore pressure distribution is formed around the tunnel; during the construction of the shield tunnel, the vertical displacement and horizontal displacement of the surrounding rock show an increasing trend and gradually tend to be stable values of 24.09 mm and 25.28 mm; the segment vault has settlement, the maximum settlement is 21.8 mm, the arch bottom has uplift, and the maximum uplift is 24.4 mm. The maximum horizontal displacement of the segment appears on both sides of the arch waist, and the maximum horizontal displacement decreases with the increase of excavation steps; the positive bending moment of the lining segment is mainly distributed on both sides of the arch crown, and the negative bending moment is mainly distributed on both sides of the arch bottom. The axial force of the lining segment is compressive stress, and the maximum axial force is mainly distributed on both sides of the arch waist. The maximum normal shear stress occurs on both sides of the segment arch bottom. The study conclusions provide theoretical foundation and a new guidance for long-term safety evaluation of underwater tunnel structures.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"57 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139483235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis on the Dynamic Behavior of Space Shafting under Combined Load","authors":"Yan Zhao, Fei Gao, Yulei Xia, Jinfang Gu, Yameng Wang, Sen Zhao","doi":"10.1155/2024/5560548","DOIUrl":"https://doi.org/10.1155/2024/5560548","url":null,"abstract":"The space shafting is the core component of the momentum exchange attitude control actuator for spacecraft.The dynamic behavior of space shafting has an important impact on the performance of the actuators. Based on the dynamic theory of rolling bearing, this paper presents a dynamic analysis model of space shafting for the interaction between bearing balls and oil-containing nonmetallic cage under combined loads. Also, the accuracy of the analysis model was verified through a high-speed camera system to conduct a cage speed test. In addition, the dynamic behavior of balls and cage under combined loads and the interaction between them is also analysed. The results show that the axial displacements of balls fluctuate periodically under combined loads, and the rotation speeds of balls and cage are easily affected by the load, presenting as the oscillation of speed. Also, the force between balls and cage increases as the load increases. The dynamic behavior of balls and cage could be effectively improved by avoiding excessive torque loads and limiting the axial preload to 40 N. The wear failure caused by unstable operation of bearings cannot be ignored. This model is more practical in completing simulation analysis of different operating conditions and structural parameters of the shafting system. It provides a theoretical reference for the structural design and performance analysis of space shafting.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":"41 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139462017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}