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.
{"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":null,"pages":null},"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}
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.
{"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":null,"pages":null},"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}
Xin Li, Weili Wang, Zhengfeng Liang, Jun Dong, Jiaojiao Tang
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.
{"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":null,"pages":null},"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}
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.
{"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":null,"pages":null},"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}
Yan Zhao, Fei Gao, Yulei Xia, Jinfang Gu, Yameng Wang, Sen Zhao
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.
{"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":null,"pages":null},"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}
Wengui Mao, Shixiong Pei, Jie Guo, Jianhua Li, Buyao Wang
Electromagnetic loads can effectively monitor motor health and improve motor design. Considering the weak correlation of the modal shape and Chebyshev orthogonal polynomial in the space-time independent electromagnetic load identification method, a proposed method combining the polynomial structure selection technique together with limited measured displacement responses is presented, in which an error reduction ratio is used to pick out the significant mode shape matrix and the Chebyshev orthogonal polynomial. The time-history function of the electromagnetic load is reconstructed by combining the significant mode shape matrix and the identified concentrated load through modal transformation, and the corresponding spatial distribution function is fitted by the significant Chebyshev orthogonal polynomial. Eventually, a comparative numerical study considering the selection of significant components and measurement noise is carried out to prove the effectiveness of the presented method.
{"title":"An Electromagnetic Load Identification Method Based on the Polynomial Structure Selection Technique","authors":"Wengui Mao, Shixiong Pei, Jie Guo, Jianhua Li, Buyao Wang","doi":"10.1155/2024/1842508","DOIUrl":"https://doi.org/10.1155/2024/1842508","url":null,"abstract":"Electromagnetic loads can effectively monitor motor health and improve motor design. Considering the weak correlation of the modal shape and Chebyshev orthogonal polynomial in the space-time independent electromagnetic load identification method, a proposed method combining the polynomial structure selection technique together with limited measured displacement responses is presented, in which an error reduction ratio is used to pick out the significant mode shape matrix and the Chebyshev orthogonal polynomial. The time-history function of the electromagnetic load is reconstructed by combining the significant mode shape matrix and the identified concentrated load through modal transformation, and the corresponding spatial distribution function is fitted by the significant Chebyshev orthogonal polynomial. Eventually, a comparative numerical study considering the selection of significant components and measurement noise is carried out to prove the effectiveness of the presented method.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139462065","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}
The popularity of new structural systems and prestressing technology has led to the widespread use of the large-space floor structures in large buildings such as high-speed rail terminals, conference centers, and sports stadiums. The reduction of nonessential load-bearing elements and the increase in span of the structure result in a reduction in the natural frequency and damping ratio of the floor structure, while the floor is a crowded area with disorderly flow between people, which may lead to human-induced vibration problems. In order to assess the dynamic performance of the large-span floor structure under crowd load, the random crowd-floor vertical interaction equation is derived, and the correctness of the equation is verified by comparing it with the test. For the stochastic nature of walking crowds, a formulation modeling method for random crowd is proposed, including pedestrian-dynamics parameters, formulation model, and response parameters. The model is characterized by considering inter- and intrasubject variability and reflects the vertical interaction between pedestrians and the floor system. According to the random crowd-floor dynamic equation, the variation of modal parameters and acceleration response of the floor during random crowd walking are also analyzed. The research in this paper will help in analyzing the comfort of large-span floor structures under pedestrian excitation and better meet the needs of the development of lightweight large-span structures.
{"title":"Dynamic Response Analysis of the Floor Structure under Random Crowd Excitation","authors":"Dong Cao, Zuanfeng Pan, Yu Fang","doi":"10.1155/2024/1451839","DOIUrl":"https://doi.org/10.1155/2024/1451839","url":null,"abstract":"The popularity of new structural systems and prestressing technology has led to the widespread use of the large-space floor structures in large buildings such as high-speed rail terminals, conference centers, and sports stadiums. The reduction of nonessential load-bearing elements and the increase in span of the structure result in a reduction in the natural frequency and damping ratio of the floor structure, while the floor is a crowded area with disorderly flow between people, which may lead to human-induced vibration problems. In order to assess the dynamic performance of the large-span floor structure under crowd load, the random crowd-floor vertical interaction equation is derived, and the correctness of the equation is verified by comparing it with the test. For the stochastic nature of walking crowds, a formulation modeling method for random crowd is proposed, including pedestrian-dynamics parameters, formulation model, and response parameters. The model is characterized by considering inter- and intrasubject variability and reflects the vertical interaction between pedestrians and the floor system. According to the random crowd-floor dynamic equation, the variation of modal parameters and acceleration response of the floor during random crowd walking are also analyzed. The research in this paper will help in analyzing the comfort of large-span floor structures under pedestrian excitation and better meet the needs of the development of lightweight large-span structures.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139410442","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}
The frequency- and temperature-dependent characteristics of viscoelastic materials significantly affect the vibration response of the damped composite structures. In this paper, an efficient strategy of hybrid expansion combined with dynamic reduction is developed to solve the steady-state response of the frequency- and temperature-dependent viscoelastic structure characterized by nonproportional system, and the sensitivity analysis is carried out based on the adjoint variable method. The similarity index is defined to distinguish the correlation among different design layouts. Two instances demonstrated the validity of the proposed approach. The findings indicated that a positive compromise between accuracy and efficiency can be achieved, and the computational time can be significantly reduced while ensuring the accuracy of the results. Furthermore, it has been discovered that the excitation frequency and temperature significantly impact the optimal configuration of damping material. The effects of layer thicknesses and volume fractions on optimization designs are also further investigated.
{"title":"Dynamic Topology Optimization of Constrained Damping Plates considering Frequency and Temperature Characteristics Based on an Efficient Strategy","authors":"Fan Wu, Pu Xue","doi":"10.1155/2024/2155470","DOIUrl":"https://doi.org/10.1155/2024/2155470","url":null,"abstract":"The frequency- and temperature-dependent characteristics of viscoelastic materials significantly affect the vibration response of the damped composite structures. In this paper, an efficient strategy of hybrid expansion combined with dynamic reduction is developed to solve the steady-state response of the frequency- and temperature-dependent viscoelastic structure characterized by nonproportional system, and the sensitivity analysis is carried out based on the adjoint variable method. The similarity index is defined to distinguish the correlation among different design layouts. Two instances demonstrated the validity of the proposed approach. The findings indicated that a positive compromise between accuracy and efficiency can be achieved, and the computational time can be significantly reduced while ensuring the accuracy of the results. Furthermore, it has been discovered that the excitation frequency and temperature significantly impact the optimal configuration of damping material. The effects of layer thicknesses and volume fractions on optimization designs are also further investigated.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139410311","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}
As coal mining gradually moves to deep earth, rock bursts have emerged as one of the main disasters threatening the safety of coal production. It is beneficial to conduct economic and effective prevention and control work by evaluating the bursting liability and improving the bursting liability evaluation system. In this paper, based on the energy transfer model, the relationship between the bursting energy index and the mechanical parameters of coal bodies is obtained by testing the bursting liability of 16 coal seams stratified in three coal mines. According to the bursting energy index and the elastic energy index, the parameter φ is defined to represent the energy release ratio of coal. This paper thus presents a method to evaluate the bursting liability as the product of the energy release ratio and energy transfer ratio and provides a definition for the energy transfer index. The results show that the bursting energy index of coal is closely related to its mechanical parameters. The prepeak deformation energy exhibits a strong positive correlation with uniaxial compressive strength and peak strain. The energy release ratio parameter φ and bursting energy index have high sensitivity and wide applicability. The results of the energy transfer index Ω = βφ are consistent with the results of bursting liability identification, which can better reflect the bursting liability, and can be used as the basis for judgment when the “” result is obtained in bursting liability identification. It is anticipated that this approach will become an important evaluation index for bursting liability identification.
{"title":"A Bursting Liability Evaluation Method Based on Energy Transfer","authors":"Yukun Hou, Shankun Zhao, Yang Zhao","doi":"10.1155/2024/7090935","DOIUrl":"https://doi.org/10.1155/2024/7090935","url":null,"abstract":"As coal mining gradually moves to deep earth, rock bursts have emerged as one of the main disasters threatening the safety of coal production. It is beneficial to conduct economic and effective prevention and control work by evaluating the bursting liability and improving the bursting liability evaluation system. In this paper, based on the energy transfer model, the relationship between the bursting energy index and the mechanical parameters of coal bodies is obtained by testing the bursting liability of 16 coal seams stratified in three coal mines. According to the bursting energy index and the elastic energy index, the parameter <i>φ</i> is defined to represent the energy release ratio of coal. This paper thus presents a method to evaluate the bursting liability as the product of the energy release ratio and energy transfer ratio and provides a definition for the energy transfer index. The results show that the bursting energy index of coal is closely related to its mechanical parameters. The prepeak deformation energy exhibits a strong positive correlation with uniaxial compressive strength and peak strain. The energy release ratio parameter <i>φ</i> and bursting energy index have high sensitivity and wide applicability. The results of the energy transfer index Ω = <i>βφ</i> are consistent with the results of bursting liability identification, which can better reflect the bursting liability, and can be used as the basis for judgment when the “<svg height=\"6.01072pt\" style=\"vertical-align:-0.04980993pt\" version=\"1.1\" viewbox=\"-0.0498162 -5.96091 7.75925 6.01072\" width=\"7.75925pt\" xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g transform=\"matrix(.013,0,0,-0.013,0,0)\"></path></g></svg>” result is obtained in bursting liability identification. It is anticipated that this approach will become an important evaluation index for bursting liability identification.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139398261","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}
In this paper, the instantaneous rock burst test of Beishan granite is carried out by using a deep rock burst simulation test system and an acoustic emission monitoring system. The acoustic emission data were monitored in real time during the test. The variation of the number and energy of acoustic emission events was studied, and the distribution characteristics of rock burst debris were analyzed. Based on plate and shell mechanics, the failure process of surrounding rock is discussed from the perspective of structural stability. The results show that (1) when the vertical stress reaches 171.31 MPa, the specimen is destroyed and the number of acoustic emission events and cumulative absolute energy before the specimen is destroyed increase sharply. (2) The debris generated by rock burst is mainly composed of slab debris, flaky debris, and thin flaky debris, accounting for 93.53% of the total debris. (3) When the length or height of the rock slab is constant, the maximum tensile stress in the rock slab decreases nonlinearly with the increase of rock slab thickness. For the same size of the rock slab, the farther away from the roadway wall, the greater the maximum tensile stress in the rock slab. (4) When the thickness of the rock slab is constant, the maximum tensile stress in the rock slab increases nonlinearly with the increase of height to thickness ratio K. When the ratio of height to thickness K is constant, the maximum tensile stress in the rock slab increases with the increase of rock slab thickness h. (5) With the increase of covering depth, the critical failure thickness of the rock slab decreases nonlinearly and the surplus energy increases nonlinearly.
本文利用深部岩爆模拟试验系统和声发射监测系统对北山花岗岩进行了瞬时岩爆试验。试验过程中实时监测了声发射数据。研究了声发射事件的数量和能量变化，分析了岩爆碎屑的分布特征。基于板壳力学，从结构稳定性的角度讨论了围岩的破坏过程。结果表明：（1）当垂直应力达到 171.31 MPa 时，试样破坏，试样破坏前的声发射事件数量和累积绝对能量急剧增加。(2）岩爆产生的碎屑主要由板状碎屑、片状碎屑和薄片状碎屑组成，占碎屑总量的 93.53%。(3）当岩板长度或高度不变时，岩板的最大拉应力随岩板厚度的增加而非线性减小。在岩板尺寸相同的情况下，离巷道壁越远，岩板的最大拉应力越大。(4) 当岩板厚度不变时，岩板最大拉应力随高厚比 K 的增大而非线性增大。
{"title":"Acoustic Emission Characteristics and Initiation Mechanism of Instantaneous Rock Burst for Beishan Granite","authors":"Chaosheng Wang, Hao Wan, Jianjun Ma, Xianglin Chen","doi":"10.1155/2024/6813580","DOIUrl":"https://doi.org/10.1155/2024/6813580","url":null,"abstract":"In this paper, the instantaneous rock burst test of Beishan granite is carried out by using a deep rock burst simulation test system and an acoustic emission monitoring system. The acoustic emission data were monitored in real time during the test. The variation of the number and energy of acoustic emission events was studied, and the distribution characteristics of rock burst debris were analyzed. Based on plate and shell mechanics, the failure process of surrounding rock is discussed from the perspective of structural stability. The results show that (1) when the vertical stress reaches 171.31 MPa, the specimen is destroyed and the number of acoustic emission events and cumulative absolute energy before the specimen is destroyed increase sharply. (2) The debris generated by rock burst is mainly composed of slab debris, flaky debris, and thin flaky debris, accounting for 93.53% of the total debris. (3) When the length or height of the rock slab is constant, the maximum tensile stress in the rock slab decreases nonlinearly with the increase of rock slab thickness. For the same size of the rock slab, the farther away from the roadway wall, the greater the maximum tensile stress in the rock slab. (4) When the thickness of the rock slab is constant, the maximum tensile stress in the rock slab increases nonlinearly with the increase of height to thickness ratio <i>K</i>. When the ratio of height to thickness <i>K</i> is constant, the maximum tensile stress in the rock slab increases with the increase of rock slab thickness <i>h</i>. (5) With the increase of covering depth, the critical failure thickness of the rock slab decreases nonlinearly and the surplus energy increases nonlinearly.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139374088","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}
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