En Wang, Shuaifeng Yin, Qifeng Zhao, Qingtao Kang, Xinjian Zheng
In response to the shortcomings of the small support scope of single anchor cable and failure to fully utilize the joint anchoring for surrounding rock, this study summarizes the classification of basic support forms for coal mine roadway surrounding rock and clarifies the main composition and mechanism of anchor cable beam-truss structure. A mechanical model of roadway roof beam under the conditions of no support, single anchor cable support, and anchor cable beam-truss structure support at both ends of the roadway is constructed, and the force and maximum bending moment of roadway roof beam under different support types are compared and analyzed. The study clarifies the bending moment reduction rate of anchor cable beam-truss structure relative to unsupported and single anchor cable support and combines numerical simulation to analyze the response laws of anchor cable beam-truss to prestress distribution and stress shell in roadway surrounding rock. Based on the on-site engineering application of a typical large-deformation mining roadway in a deep coal mine, the important role of anchor cable beam-truss structure in ensuring the safety and stability of surrounding rock in deep high-stress and intense-mining large-deformation roadway is revealed, providing technical references for surrounding rock control of similar conditions in deep roadways.
{"title":"Control Effect Analysis and Engineering Application of Anchor Cable Beam-Truss Structure on Large-Deformation Roadway in Deep Coal Mine","authors":"En Wang, Shuaifeng Yin, Qifeng Zhao, Qingtao Kang, Xinjian Zheng","doi":"10.1155/2024/2987574","DOIUrl":"https://doi.org/10.1155/2024/2987574","url":null,"abstract":"In response to the shortcomings of the small support scope of single anchor cable and failure to fully utilize the joint anchoring for surrounding rock, this study summarizes the classification of basic support forms for coal mine roadway surrounding rock and clarifies the main composition and mechanism of anchor cable beam-truss structure. A mechanical model of roadway roof beam under the conditions of no support, single anchor cable support, and anchor cable beam-truss structure support at both ends of the roadway is constructed, and the force and maximum bending moment of roadway roof beam under different support types are compared and analyzed. The study clarifies the bending moment reduction rate of anchor cable beam-truss structure relative to unsupported and single anchor cable support and combines numerical simulation to analyze the response laws of anchor cable beam-truss to prestress distribution and stress shell in roadway surrounding rock. Based on the on-site engineering application of a typical large-deformation mining roadway in a deep coal mine, the important role of anchor cable beam-truss structure in ensuring the safety and stability of surrounding rock in deep high-stress and intense-mining large-deformation roadway is revealed, providing technical references for surrounding rock control of similar conditions in deep roadways.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141146627","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}
Lei Wang, Wen Nie, Ming Xie, Zi Wang, Wei Lu, Dongmei Chen, Weinan Lin
The internal defects of rocks are the main cause of instability and failure in underground engineering. Therefore, using ultrasonic monitoring technology to study the defect characteristics of rocks containing voids is of great significance. The research results indicate that with the increase in the pore size, the longitudinal wave velocity and first wave amplitude of rocks containing voids decrease, the attenuation coefficient increases, and the difference in ultrasonic parameters between rocks containing voids and intact rocks increases, resulting in a significant decrease in the rock integrity. The propagation of ultrasonic waves in porous rocks can be divided into three stages, where obvious ultrasonic reflection, diffraction, and scattering occur. The attenuation of sound pressure is significant, and the ultrasonic sound pressure is negatively linearly correlated with the pore size. Based on the amplitude, velocity, and pressure of ultrasonic waves, an ANN-based method for predicting the pore size of rocks is proposed, which inverts and predicts the pore size of rock masses with high prediction accuracy.
岩石的内部缺陷是地下工程失稳和破坏的主要原因。因此，利用超声波监测技术研究含空隙岩石的缺陷特征具有重要意义。研究结果表明，随着孔隙的增大，含空隙岩石的纵波速度和第一波振幅减小，衰减系数增大，含空隙岩石与完整岩石之间的超声波参数差异增大，导致岩石完整性显著降低。超声波在多孔岩石中的传播可分为三个阶段，分别发生明显的超声波反射、衍射和散射。声压衰减明显，超声声压与孔隙大小呈负线性关系。基于超声波的振幅、速度和压力，提出了一种基于 ANN 的岩石孔隙度预测方法，该方法可反演和预测岩体的孔隙度，预测精度高。
{"title":"Study on Ultrasonic Characteristics and Prediction of Rock with Different Pore Sizes","authors":"Lei Wang, Wen Nie, Ming Xie, Zi Wang, Wei Lu, Dongmei Chen, Weinan Lin","doi":"10.1155/2024/5060571","DOIUrl":"https://doi.org/10.1155/2024/5060571","url":null,"abstract":"The internal defects of rocks are the main cause of instability and failure in underground engineering. Therefore, using ultrasonic monitoring technology to study the defect characteristics of rocks containing voids is of great significance. The research results indicate that with the increase in the pore size, the longitudinal wave velocity and first wave amplitude of rocks containing voids decrease, the attenuation coefficient increases, and the difference in ultrasonic parameters between rocks containing voids and intact rocks increases, resulting in a significant decrease in the rock integrity. The propagation of ultrasonic waves in porous rocks can be divided into three stages, where obvious ultrasonic reflection, diffraction, and scattering occur. The attenuation of sound pressure is significant, and the ultrasonic sound pressure is negatively linearly correlated with the pore size. Based on the amplitude, velocity, and pressure of ultrasonic waves, an ANN-based method for predicting the pore size of rocks is proposed, which inverts and predicts the pore size of rock masses with high prediction accuracy.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141107119","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}
Chengfu Ma, Fenghai Yu, Kai Zhou, Xuerui Yang, Bo Sun, Xinyu Yao, Yani Chi, Yuanzhi Zhang
Under the condition of weakly cemented soft rock in Western China, the surrounding rock deformation of gob-side entry is obvious, especially under the influence of fault, and the problem of surrounding rock control becomes increasingly prominent. To solve this issue, this paper firstly studied and obtained the evolution law of the ground pressure appearance of the gob-side entry in the fault area, then put forward the concept of surrounding rock control in the fault area of the gob-side entry, put forward a targeted pressure relief + increase preload + passive reinforcement parallel to the roadway surrounding rock strengthening control scheme, and carried out field applications. The results show that the roof subsidence and mining side heave of the roadway in the fault area increase significantly, accompanied by the characteristics of broken cables, the length of the broken cable is 0.2 m–0.6 m, and the breaking process is divided into multiple breaks. The stress evolution of gob-side entry in fault area presents a stage characteristic of “rapid growth-stable.” The surrounding rock control effect is improved under the bolt cable high pre-tightening support, and the roadway deformation is effectively controlled under the pressure relief + active + passive support, with a good application effect.
{"title":"Deformation and Failure Evolution Law and Support Optimization of Gob-Side Entry in Weakly Cemented Soft Rock under the Influence of Fault","authors":"Chengfu Ma, Fenghai Yu, Kai Zhou, Xuerui Yang, Bo Sun, Xinyu Yao, Yani Chi, Yuanzhi Zhang","doi":"10.1155/2024/3198333","DOIUrl":"https://doi.org/10.1155/2024/3198333","url":null,"abstract":"Under the condition of weakly cemented soft rock in Western China, the surrounding rock deformation of gob-side entry is obvious, especially under the influence of fault, and the problem of surrounding rock control becomes increasingly prominent. To solve this issue, this paper firstly studied and obtained the evolution law of the ground pressure appearance of the gob-side entry in the fault area, then put forward the concept of surrounding rock control in the fault area of the gob-side entry, put forward a targeted pressure relief + increase preload + passive reinforcement parallel to the roadway surrounding rock strengthening control scheme, and carried out field applications. The results show that the roof subsidence and mining side heave of the roadway in the fault area increase significantly, accompanied by the characteristics of broken cables, the length of the broken cable is 0.2 m–0.6 m, and the breaking process is divided into multiple breaks. The stress evolution of gob-side entry in fault area presents a stage characteristic of “rapid growth-stable.” The surrounding rock control effect is improved under the bolt cable high pre-tightening support, and the roadway deformation is effectively controlled under the pressure relief + active + passive support, with a good application effect.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140968428","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}
Fenghai Yu, Bo Sun, Qingduo Wang, Ping Fang, Tao Zhang, Jianchong Chen, Xin Zhao, Dehe Zhu
The magnitude of pretension force serves as an important indicator of the effectiveness of anchor bolt active support and is one of the significant factors influencing the stability of tunnel surrounding rock. Therefore, in practical engineering, it is crucial to establish the relationship between pretension torque and pretension force. However, current research in this field has some limitations. With a specific mine in western China as the engineering background, this paper first analyzed the influence factors of surrounding rock deformation and failure, established a mechanical model for pretension structure of anchor bolt support, and derived the quantitative relationship between pretension torque and pretension force based on hypothetical conditions. Finally, it proposed the loss effect of anchor bolt support and modified the pretightening loss coefficient for engineering application. The research results show that the actual pretightening force of anchor support is lower due to the influence of deep soft coal seam, which leads to failure of coal pillar under mining stress. The loss effect of surrounding rock on pretightening force was represented by a coefficient k, and the modified value of the coefficient was calculated as 0.19∼0.43. By applying the modified relationship between pretightening torque and pretightening force, it was found that the actual pretightening torque of 300 Nm applied to 11307 return air roadway effectively controlled surrounding rock deformation and failure, with coal pillar displacement less than 120 mm.
预紧力的大小是衡量锚杆主动支护效果的重要指标，也是影响隧道围岩稳定性的重要因素之一。因此，在实际工程中，建立预紧扭矩与预紧力之间的关系至关重要。然而，目前该领域的研究还存在一定的局限性。本文以中国西部某矿山为工程背景，首先分析了围岩变形和破坏的影响因素，建立了锚杆支护预紧结构的力学模型，并基于假设条件得出了预紧力矩与预紧力之间的定量关系。最后，提出了锚杆支护的损失效应，并修正了工程应用中的预紧损失系数。研究结果表明，由于受到深厚软煤层的影响，锚杆支护的实际预紧力较小，导致煤柱在开采应力作用下失效。围岩对预紧力的损失效应用系数 k 表示，计算得出该系数的修正值为 0.19∼0.43。根据修正后的预紧力矩与预紧力关系，11307 回风巷道实际预紧力矩为 300 Nm，有效控制了围岩变形和破坏，煤柱位移小于 120 mm。
{"title":"Study on Pretightening Loss Effect of Bolt Support in Deep Soft Rock Roadway","authors":"Fenghai Yu, Bo Sun, Qingduo Wang, Ping Fang, Tao Zhang, Jianchong Chen, Xin Zhao, Dehe Zhu","doi":"10.1155/2024/3834064","DOIUrl":"https://doi.org/10.1155/2024/3834064","url":null,"abstract":"The magnitude of pretension force serves as an important indicator of the effectiveness of anchor bolt active support and is one of the significant factors influencing the stability of tunnel surrounding rock. Therefore, in practical engineering, it is crucial to establish the relationship between pretension torque and pretension force. However, current research in this field has some limitations. With a specific mine in western China as the engineering background, this paper first analyzed the influence factors of surrounding rock deformation and failure, established a mechanical model for pretension structure of anchor bolt support, and derived the quantitative relationship between pretension torque and pretension force based on hypothetical conditions. Finally, it proposed the loss effect of anchor bolt support and modified the pretightening loss coefficient for engineering application. The research results show that the actual pretightening force of anchor support is lower due to the influence of deep soft coal seam, which leads to failure of coal pillar under mining stress. The loss effect of surrounding rock on pretightening force was represented by a coefficient <i>k</i>, and the modified value of the coefficient was calculated as 0.19∼0.43. By applying the modified relationship between pretightening torque and pretightening force, it was found that the actual pretightening torque of 300 Nm applied to 11307 return air roadway effectively controlled surrounding rock deformation and failure, with coal pillar displacement less than 120 mm.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939635","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}
This article investigates the movement of concrete subjected to vibration employing mass-spring model. For this purpose, two different prefabricated concrete-formworks, on which experimental work was done before, were analysed analytically. The theoretical modeling of precast formworks employed in experiments has been made by the three-dimensional finite element method employing the SAP2000 program. Modeling of mortar is performed to resolve the interaction between the fresh concrete and formwork using the mass-spring model. Considering the dynamic behavior of the fluid, it is possible to define multiple oscillation (convective) masses with different frequency values in addition to the impulse mass. Thus, one impulse mass and two convective masses were used in the mass-spring model. This study is essentially theoretical, and its accuracy has been strengthened by experimental work. The time-dependent results of concrete movement obtained from the dynamic mass-spring model were compared with the measured ones. The matches indicate that the findings are consistent.
{"title":"Examination of Precast Concrete Movement Subjected to Vibration Employing Mass-Spring Model with Two Convective Masses","authors":"Gultekin Aktas","doi":"10.1155/2024/6341133","DOIUrl":"https://doi.org/10.1155/2024/6341133","url":null,"abstract":"This article investigates the movement of concrete subjected to vibration employing mass-spring model. For this purpose, two different prefabricated concrete-formworks, on which experimental work was done before, were analysed analytically. The theoretical modeling of precast formworks employed in experiments has been made by the three-dimensional finite element method employing the SAP2000 program. Modeling of mortar is performed to resolve the interaction between the fresh concrete and formwork using the mass-spring model. Considering the dynamic behavior of the fluid, it is possible to define multiple oscillation (convective) masses with different frequency values in addition to the impulse mass. Thus, one impulse mass and two convective masses were used in the mass-spring model. This study is essentially theoretical, and its accuracy has been strengthened by experimental work. The time-dependent results of concrete movement obtained from the dynamic mass-spring model were compared with the measured ones. The matches indicate that the findings are consistent.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939808","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}
A novel split-type air conditioning system is introduced to balance usability and portability. Unlike conventional split-type systems, where the compressor is typically placed outside, this system situates the compressor within the indoor unit, which may expose users to compressor noise. There are prominent peaks in the compressor noise spectrum, particularly at the compressor operating frequency and its harmonics, notably the second and third harmonics. The research presents a multilayered acoustic enclosure specifically designed for air conditioning compressors to address this issue without modifying the compressor or indoor unit casing. In order to get better sound insulation performance, a response surface methodology (RSM) is applied to optimize the thickness ratio, open area ratio, and open area height of the acoustic enclosure with predefined thickness. In addition, topological optimization is employed to strengthen weak areas of the acoustic enclosure. Then, experimental trials using the proposed acoustic enclosure are conducted in a semianechoic chamber. Results demonstrate significant reductions in noise levels, including 7.99 dB(A), 5.69 dB(A), and 5.19 dB(A) reductions in the fundamental frequency, second harmonic, and third harmonic noise of the compressor’s operating frequency, respectively.
{"title":"An Investigation of the Acoustic Enclosure of an Air Conditioning Compressor Using Response Surface Analysis and Topological Rigidity Optimization","authors":"Hai-Feng Cao, Cang-Jie Yang, Ren-Lian Ma, Shi-Wei Ni, Zheng-Kai Song, Xi Wang, Yu-Xuan Chen, Chen-Xing Jiang","doi":"10.1155/2024/1909530","DOIUrl":"https://doi.org/10.1155/2024/1909530","url":null,"abstract":"A novel split-type air conditioning system is introduced to balance usability and portability. Unlike conventional split-type systems, where the compressor is typically placed outside, this system situates the compressor within the indoor unit, which may expose users to compressor noise. There are prominent peaks in the compressor noise spectrum, particularly at the compressor operating frequency and its harmonics, notably the second and third harmonics. The research presents a multilayered acoustic enclosure specifically designed for air conditioning compressors to address this issue without modifying the compressor or indoor unit casing. In order to get better sound insulation performance, a response surface methodology (RSM) is applied to optimize the thickness ratio, open area ratio, and open area height of the acoustic enclosure with predefined thickness. In addition, topological optimization is employed to strengthen weak areas of the acoustic enclosure. Then, experimental trials using the proposed acoustic enclosure are conducted in a semianechoic chamber. Results demonstrate significant reductions in noise levels, including 7.99 dB(A), 5.69 dB(A), and 5.19 dB(A) reductions in the fundamental frequency, second harmonic, and third harmonic noise of the compressor’s operating frequency, respectively.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939736","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}
Truong Duc Phuc, Phuc Hong Pham, Kien Trung Hoang, Bui Ngoc-Tam
This article proposes a formula for calculating the nonlinear displacement of the electrothermal V-shaped actuator aims to determine more accurately its displacement. The nonlinear displacement model is established based on the axial deformation of V-beams with two fixed ends. Hence, the theoretical displacements of a particular V-shaped actuator (i.e. dimension as beam length of 750 μm; beam width of 6 μm; beam thickness of 30 μm; inclined angle of 2°) are compared with the simulation and experimental results. The evaluation shows that our calculation error compared with the simulation and experiment is less than 5% and 12.4%, respectively. This confirmed the advantages of the proposed formula according to the nonlinear displacement model. This work provides a theoretical model for predicting more precisely the displacement of a V-shaped actuator. The advantage of this model is that it will significantly reduce the time in the design and trial manufacturing process.
本文提出了电热 V 型推杆的非线性位移计算公式，旨在更精确地确定其位移。非线性位移模型是根据两端固定的 V 形梁的轴向变形建立的。因此，我们将特定 V 型致动器（即尺寸为梁长 750 μm；梁宽 6 μm；梁厚 30 μm；倾斜角 2°）的理论位移与模拟和实验结果进行了比较。评估结果表明，与模拟和实验结果相比，我们的计算误差分别小于 5%和 12.4%。这证实了根据非线性位移模型提出的计算公式的优势。这项研究为更精确地预测 V 型推杆的位移提供了一个理论模型。该模型的优点是可以大大缩短设计和试制过程的时间。
{"title":"Nonlinear Displacement of the Electrothermal V-Shaped Actuator","authors":"Truong Duc Phuc, Phuc Hong Pham, Kien Trung Hoang, Bui Ngoc-Tam","doi":"10.1155/2024/7121490","DOIUrl":"https://doi.org/10.1155/2024/7121490","url":null,"abstract":"This article proposes a formula for calculating the nonlinear displacement of the electrothermal V-shaped actuator aims to determine more accurately its displacement. The nonlinear displacement model is established based on the axial deformation of V-beams with two fixed ends. Hence, the theoretical displacements of a particular V-shaped actuator (i.e. dimension as beam length of 750 <i>μ</i>m; beam width of 6 <i>μ</i>m; beam thickness of 30 <i>μ</i>m; inclined angle of 2°) are compared with the simulation and experimental results. The evaluation shows that our calculation error compared with the simulation and experiment is less than 5% and 12.4%, respectively. This confirmed the advantages of the proposed formula according to the nonlinear displacement model. This work provides a theoretical model for predicting more precisely the displacement of a V-shaped actuator. The advantage of this model is that it will significantly reduce the time in the design and trial manufacturing process.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830752","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 study, the vibration characteristics of a bullet-loaded recorder’s vibration damping system under various preload conditions are investigated through theoretical analysis, numerical simulations, and experimental verification. The findings indicate that the inclusion of a polyurethane elastomer vibration damping buffer layer between the cartridge and the recorder, along with the application of a specific preload, significantly reduces the amplitude of vibration acceleration transmitted to the recorder’s interior. This, in turn, enhances the overload resistance of the cartridge’s internal circuit. Numerical simulation results and theoretical analysis suggest that increasing the preload on the buffer material between the elastomer and the recorder reduces both the frequency ratio and damping ratio of the damping system. This reduction further decreases the amplitude of vibration transmitted to the recorder. However, excessively high preload generates substantial compressive stress within the recorder under static conditions, intensifying during the projectile’s accelerated movement. As a consequence, deformation and damage occur to the internal circuitry. Therefore, ensuring that the recorder possesses the structural strength necessary to withstand increased preload is crucial. This balancing act improves the recorder’s resistance to shock, vibration, and overload, while also preventing excessive stress-induced damage.
{"title":"Researching the Influence of Preload on Vibration Characteristics in the Ballistic Recorder Vibration Damping System","authors":"Wencan Jiang, Yonggang Lu, Jianyu Zhao","doi":"10.1155/2024/5868224","DOIUrl":"https://doi.org/10.1155/2024/5868224","url":null,"abstract":"In this study, the vibration characteristics of a bullet-loaded recorder’s vibration damping system under various preload conditions are investigated through theoretical analysis, numerical simulations, and experimental verification. The findings indicate that the inclusion of a polyurethane elastomer vibration damping buffer layer between the cartridge and the recorder, along with the application of a specific preload, significantly reduces the amplitude of vibration acceleration transmitted to the recorder’s interior. This, in turn, enhances the overload resistance of the cartridge’s internal circuit. Numerical simulation results and theoretical analysis suggest that increasing the preload on the buffer material between the elastomer and the recorder reduces both the frequency ratio and damping ratio of the damping system. This reduction further decreases the amplitude of vibration transmitted to the recorder. However, excessively high preload generates substantial compressive stress within the recorder under static conditions, intensifying during the projectile’s accelerated movement. As a consequence, deformation and damage occur to the internal circuitry. Therefore, ensuring that the recorder possesses the structural strength necessary to withstand increased preload is crucial. This balancing act improves the recorder’s resistance to shock, vibration, and overload, while also preventing excessive stress-induced damage.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830746","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}
Zhang Kun, Li Hongren, Wang Xin, Xie Daxing, Sun Xiaokai
This paper introduces an innovative approach, Deep Multiscale Soft-Threshold Support Vector Data Description (DMS-SVDD), designed for the detection of anomalies and prediction of faults in heavy-duty gas turbine generator sets (GENSETs). The model combines a support vector data description (SVDD) with a deep autoencoder backbone network framework, integrating a multiscale convolutional neural network (M) and soft-threshold activation network (S) into the Deep-SVDD framework. In comparison with conventional methods, such as One-Class Support Vector Machine (OCSVM) and autoencoder (AE), DMS-SVDD demonstrates improvements in accuracy (by 22.94%), recall (by 32%), F1 score (by 12.02%), and smoothness (by 39.15%). The model excels particularly in feature extraction, denoising, and early fault detection, offering a proactive strategy for maintenance. Furthermore, the DMS-SVDD demonstrated enhanced training efficiency with a reduction in the convergence rounds by 66% and overall training times by 34.13%. The study concludes that DMS-SVDD presents a robust and efficient solution for gas turbine anomaly detection, with practical advantages for decision support in turbine maintenance. Future research could explore additional refinements and applications of the DMS-SVDD model across diverse industrial contexts.
{"title":"Deep Multiscale Soft-Threshold Support Vector Data Description for Enhanced Heavy-Duty Gas Turbine Generator Sets’ Anomaly Detection","authors":"Zhang Kun, Li Hongren, Wang Xin, Xie Daxing, Sun Xiaokai","doi":"10.1155/2024/3374107","DOIUrl":"https://doi.org/10.1155/2024/3374107","url":null,"abstract":"This paper introduces an innovative approach, Deep Multiscale Soft-Threshold Support Vector Data Description (DMS-SVDD), designed for the detection of anomalies and prediction of faults in heavy-duty gas turbine generator sets (GENSETs). The model combines a support vector data description (SVDD) with a deep autoencoder backbone network framework, integrating a multiscale convolutional neural network (M) and soft-threshold activation network (S) into the Deep-SVDD framework. In comparison with conventional methods, such as One-Class Support Vector Machine (OCSVM) and autoencoder (AE), DMS-SVDD demonstrates improvements in accuracy (by 22.94%), recall (by 32%), F1 score (by 12.02%), and smoothness (by 39.15%). The model excels particularly in feature extraction, denoising, and early fault detection, offering a proactive strategy for maintenance. Furthermore, the DMS-SVDD demonstrated enhanced training efficiency with a reduction in the convergence rounds by 66% and overall training times by 34.13%. The study concludes that DMS-SVDD presents a robust and efficient solution for gas turbine anomaly detection, with practical advantages for decision support in turbine maintenance. Future research could explore additional refinements and applications of the DMS-SVDD model across diverse industrial contexts.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140810158","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}
Using the monitoring temperature field data from the flat steel box girder, the time histories of temperature data and temperature difference data are investigated using the extreme value analysis method. Because the calculation of standard values of temperature action needs massive temperature field data, the simulation of daily extreme values of temperature data and temperature difference data is carried out by virtual of Probability Statistical Method. The seasonal and nonstationary trend terms are described using the weighted sum of a series of basic elementary functions. The random fluctuation term is represented by a joint model of ARMA mean and GARCH variance. Moreover, the yearly extreme values of temperature data and temperature difference data are considered as statistical variables, and their standard values of temperature action with 50-year return period are calculated by means of the general extreme value (GEV) distributive function. The research results can supply references for temperature action of flat steel box girder.
利用平板钢箱梁的监测温度场数据，采用极值分析方法研究了温度数据和温差数据的时间历程。由于温度作用标准值的计算需要大量的温度场数据，因此采用概率统计法对温度数据和温差数据的日极值进行了模拟。季节和非平稳趋势项使用一系列基本基本函数的加权和来描述。随机波动项由 ARMA 均值和 GARCH 方差联合模型表示。此外，还将气温数据和温差数据的年极端值视为统计变量，并通过一般极端值（GEV）分配函数计算其 50 年回归期气温作用的标准值。研究结果可为扁平钢箱梁的温度作用提供参考。
{"title":"Calculation of Temperature Action of Flat Steel Box Girder of Long-Span Bridges Using a Joint Model of ARMA Mean and GARCH Variance","authors":"Jun Yang, Dacheng Zhao, Bin Chen, Gaoxin Wang","doi":"10.1155/2024/1948140","DOIUrl":"https://doi.org/10.1155/2024/1948140","url":null,"abstract":"Using the monitoring temperature field data from the flat steel box girder, the time histories of temperature data and temperature difference data are investigated using the extreme value analysis method. Because the calculation of standard values of temperature action needs massive temperature field data, the simulation of daily extreme values of temperature data and temperature difference data is carried out by virtual of Probability Statistical Method. The seasonal and nonstationary trend terms are described using the weighted sum of a series of basic elementary functions. The random fluctuation term is represented by a joint model of ARMA mean and GARCH variance. Moreover, the yearly extreme values of temperature data and temperature difference data are considered as statistical variables, and their standard values of temperature action with 50-year return period are calculated by means of the general extreme value (GEV) distributive function. The research results can supply references for temperature action of flat steel box girder.","PeriodicalId":21915,"journal":{"name":"Shock and Vibration","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140802946","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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