Acta Mechanica Sinica最新文献

{"title":"How does the shape of an inclusion near a bi-material interface evolve to maintain uniform internal stress: the anti-plane shear case","authors":"Ming Dai \u0000 (,&nbsp;),&nbsp;Cun-Fa Gao \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24604-x","DOIUrl":"10.1007/s10409-024-24604-x","url":null,"abstract":"<div><p>In the theory of two-dimensional linear elasticity, an elliptical inclusion is known to attain a constant stress field when perfectly buried in an infinite homogeneous matrix if a uniform eigenstrain is applied to it. The focus of this paper falls on the question: when the initially elliptical inclusion verges on a bi-material interface, what would happen to its configuration if it is required to retain the internal constant stress? Specifically, we explore the anti-plane shear version of this question (the version of plane deformations or three-dimensional deformations seems, however, insoluble at this stage), in which an inclusion undergoing a uniform (anti-plane shear) eigenstrain is embedded in a bi-material structure composed of two infinite elastic half-planes whose interface is straight and perfectly bonded, and the shape of the inclusion is to be determined such that the eigenstrain-induced stress inside the inclusion appears to be a constant. Unlike most optimization methods-driven solution procedures for finding the shape of the inclusion approximately in which huge computation is required, we derive by a rigorous theoretical analysis an exact integral equation with respect to the boundary curve of the inclusion that is sufficiently and necessarily related to the existence of a constant stress inside the inclusion. We solve this integral equation via the use of some analytic techniques and present in several illustrative examples a variety of shapes of the inclusion achieving constant stresses. We discover some interesting phenomena for the evolution of the shape of the uniformly stressed inclusion relative to the stiffness of the nearby interface.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Yaw angle effect on flat plate impact and its critical value analysis","authors":"Jingtian Ma \u0000 (,&nbsp;),&nbsp;Xiaowei Chen \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24395-x","DOIUrl":"10.1007/s10409-024-24395-x","url":null,"abstract":"<div><p>Flat plate impact experiments are crucial in assessing the dynamic mechanical properties of materials. However, yaw angle tolerances always affect the accuracy of the results. To analyze this effect, this study conducted numerical simulations and theoretical derivations of non-ideal plate impacts. By comparing the simulated results of spallation, shock wave propagation, and free surface velocity, laws governing the effect of yaw angle on the plate impact were summarized. We observed that yaw angles influence the wave-action time and the shape of the compression zone, which affects the trigger and location of spallation and the free surface velocity of the target. Additionally, the yaw angle diminishes the kinetic energy of the target. When the yaw angle exceeds 2°, a significant energy reduction occurs as the shock wave propagates, which results in insufficient energy for complete spallation. Our analyses led to proposing methods for determining the critical yaw angle in plate impact experiments and to introducing a multipoint-velocimetry approach to calculate the non-ideal impact posture of the flyer. Notably, the findings revealed that 0.2° could serve as the critical yaw angle in certain scenarios. Leveraging these research outcomes judiciously can aid in assessing experimental deviations effectively and optimizing experimental costs.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 11","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Semi-analytical approach for magneto-fluid-solid interaction dynamics of thin rectangular column","authors":"Jing-Yu Fu \u0000 (,&nbsp;),&nbsp;Ming-Jiu Ni \u0000 (,&nbsp;),&nbsp;Nian-Mei Zhang \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24337-x","DOIUrl":"10.1007/s10409-024-24337-x","url":null,"abstract":"<div><p>This work focuses on the fluid-rigid interaction dynamics in the presence of a magnetic field. A rigid thin rectangular column immersed inside stationary metal liquid vibrates with a fixed small amplitude. The magneto-fluid-solid interaction (MFSI) dynamics issue is studied based on the complex Green’s function method. Considering either the normal or tangential vibration of a column, two types of semi-analytical solutions expressed by stream function integral equations of magnetic corrections, describing the time-displacement history of the column, flow field and electrical potential field of metal fluid and representing transient coupling effects of multi-physics field, are derived, respectively. Nonuniform discretization schemes and an iterative plan are applied to evaluate added damping and inertial loads. The results show that the main factor affecting normal vibration is pressure load, and the main factor affecting tangential vibration is vorticity load. The nonlinear effects of magnetic fields on the dynamics of fluid-rigid thin columns are revealed. The normal vibration exhibits better stability than the tangential vibration under the magnetic field. The induced electrical potential field and current intensity excited by normal vibration are significantly stronger than that of tangential vibration. These semi-analytical solutions can be applied as benchmarks in future validation and verification works for MFSI numerical algorithms for magnetic confinement nuclear fusion science.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 9","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 the practical applicability of the generalized wave impedance hypothesis in split Hopkinson pressure bar tests","authors":"Yiding Wu \u0000 (,&nbsp;),&nbsp;Wencheng Lu \u0000 (,&nbsp;),&nbsp;Xuan Zhou \u0000 (,&nbsp;),&nbsp;Minghui Ma \u0000 (,&nbsp;),&nbsp;Yilei Yu \u0000 (,&nbsp;),&nbsp;Lizhi Xu \u0000 (,&nbsp;),&nbsp;Guangfa Gao \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24388-x","DOIUrl":"10.1007/s10409-024-24388-x","url":null,"abstract":"<div><p>This paper explores the applicability of the generalized wave impedance hypothesis in split Hopkinson pressure bar (SHPB) experiments, particularly under non-ideal conditions. The study investigates the effects of changes in wave impedance ratio and cross-sectional area ratio on the dynamic response of materials at high strain rates. Through theoretical analysis and numerical simulation, the impact of different wave impedance and cross-sectional area ratios on stress wave propagation characteristics is discussed in detail. It is found that when the cross-sections of two bars differ, shear strain occurs at the abrupt cross-section, leading to waveform distortion in the transmitted and reflected waves. The force balance condition does not always align with the momentum conservation theorem, and only when the three waveforms and wavelengths are completely consistent do they align. The research shows that when the wave impedance ratio and cross-sectional area ratio are within a specific range, the generalized wave impedance hypothesis can accurately predict changes in Young’s modulus and density. Additionally, the study extends the exploration to key factors such as wave impedance ratio, wave speed, Young’s modulus, density, and area ratio.\u0000</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sound field prediction and management in irregular enclosures subjected to piping system excitation","authors":"Xiangliang Wang \u0000 (,&nbsp;),&nbsp;Dongwei Wang \u0000 (,&nbsp;),&nbsp;Yun Ma \u0000 (,&nbsp;),&nbsp;Gengkai Hu \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24559-x","DOIUrl":"10.1007/s10409-024-24559-x","url":null,"abstract":"<div><p>The sound field driven by piping systems in enclosures may severely affect living comfort, which is frequently encountered in various engineering applications. Managing this sound field relies heavily on the available prediction tools at hand, e.g., the widely used finite element methods are computationally expensive due to the necessity to discretize entire space, analytical models, based on modal expansion method, may offer substantial advantages in terms of computational cost and efficiency. However, deriving eigenmodes of irregular enclosed spaces may be challenging, which impedes accurate and rapid predictions of the sound field in practical applications. This study presents an analytical framework aimed at rapidly and accurately predicting the interior sound field driven by the piping system vibrations in irregular enclosures. Vibration response of the piping system is obtained using the wave approach, and a line dipole source is idealized as the sound source of the piping system vibration. On the basis of eigenmodes of regular enclosures, the Kirchhoff-Helmholtz integral theorem (modal expansion method for irregular enclosures) is introduced to account for the boundaries of irregular enclosures. This theoretical framework is validated through numerical simulations by finite element method and experiments, demonstrating high accuracy and significant efficiency advantages. The proposed method can be further employed to optimize radiated sound fields by tailoring the impedance of space walls or layout of piping systems. This study provides an efficient tool for predicting radiated sound field in general enclosures driven by vibration of piping systems, paving a new path for indoor acoustical optimization.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 11","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 of the biomechanics of osteoarthritis of the knee by pulsed electrical stimulation","authors":"Yanru Xue \u0000 (,&nbsp;),&nbsp;Zekun Hua \u0000 (,&nbsp;),&nbsp;Xinqi Lou \u0000 (,&nbsp;),&nbsp;Yinuo Zhao \u0000 (,&nbsp;),&nbsp;Ying Shen \u0000 (,&nbsp;),&nbsp;Meng Zhang \u0000 (,&nbsp;),&nbsp;Haoyu Feng \u0000 (,&nbsp;),&nbsp;Xiaochun Wei \u0000 (,&nbsp;),&nbsp;Yanqin Wang \u0000 (,&nbsp;),&nbsp;Xiaogang Wu \u0000 (,&nbsp;),&nbsp;Weiyi Chen \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24489-x","DOIUrl":"10.1007/s10409-024-24489-x","url":null,"abstract":"<div><p>Osteoarthritis is one of the most common joint diseases, leading to joint pain, dysfunction, and a reduced quality of life for patients. Therefore, it is particularly important to explore more effective prevention, treatment and management methods to relieve patients’ pain and enhance their quality of life. Among physical therapies, pulsed electrical stimulation (PES) is considered to be a promising treatment method due to its high safety and ease-of-use features. PES provides a non-invasive, safe and effective option for patients. However, there are fewer studies on the biomechanical changes of PES in periarticular tissues, and its effects on the biological behavior of chondrocytes remain unknown. This study investigated the effects of PES on the biomechanical properties of osteoarthritic joints and the biological behavior of chondrocytes. The results showed that PES with an intensity of 10 mA and a frequency of 4 Hz increased the cross-sectional area of muscle fibers, prevented muscle atrophy and loss of function, and restored the mechanical properties of muscle tissue. PES also effectively increases the resistivity of knee osteoarthritis cartilage tissue, as well as the elastic modulus of cartilage, which can enhance the biomechanical characteristics of cartilage tissue. PES also promoted the metabolic activity of chondrocytes and increased cartilage matrix synthesis, thereby improving the overall structure and mechanical properties of cartilage tissue. Additionally, cellular experiments showed that 5 consecutive days of 800 mV PES significantly increased the expression level of Piezo1 gene in chondrocytes. At the same time, the expression of type II collagen and transforming growth factor beta increased, while the expression of matrix metallopeptidase 13 decreased. These changes favored the promotion of cartilage matrix synthesis. This has a positive effect on protecting and improving joint health and reducing the impact of osteoarthritis, and is important for understanding the mechanism of action of PES on chondrocytes and the development of related therapeutic strategies.</p></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143466039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of heat-release rate distribution on the propagation stability of detonation waves","authors":"Kepeng Yao \u0000 (,&nbsp;),&nbsp;Chun Wang \u0000 (,&nbsp;),&nbsp;Guilai Han \u0000 (,&nbsp;),&nbsp;Zonglin Jiang \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24519-x","DOIUrl":"10.1007/s10409-024-24519-x","url":null,"abstract":"<div><p>The distribution of exothermic reaction rates is jointly influenced by reduced activation energy and reaction rate constant. This study focuses on the effect of distribution of exothermic reaction rates on detonation wave propagation instability, specifically under conditions where the length of the induction and exothermic reaction remains constant. It is found that the distribution variation of exothermic reaction rates significantly influences the detonation wave propagation characteristics. Specifically, under conditions of high activation energy, the exothermic reaction rate profile exhibits a smoother distribution but becomes more prone to perturbations. This heightened sensitivity, coupled with the augmented overdriven degree associated with pulsating detonation and cellular detonation wave propagation, further exacerbates the instability characteristics of detonation waves. Especially to the two-dimensional detonation waves with high activation energies, the distribution of exothermic reaction rates becomes more sensitive to these displacements, reinforcing the transverse shock wave and leading to a transformation of the wavefront and cellular structure towards more unstable configurations. This research delves into the intricate interactions between the distribution of exothermic reaction rates and detonation wave instability, aiming to provide an explanatory of detonation instability.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 10","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of temperature and atmosphere on the fracture toughness and failure mechanisms of two-dimensional plain-woven SiCf/SiC composites: Experiments and modeling","authors":"Yong Deng \u0000 (,&nbsp;),&nbsp;Yi Hao \u0000 (,&nbsp;),&nbsp;Huanfang Wang \u0000 (,&nbsp;),&nbsp;Weiguo Li \u0000 (,&nbsp;),&nbsp;Qiang Qin \u0000 (,&nbsp;),&nbsp;Bing Pan \u0000 (,&nbsp;),&nbsp;Chao Zhang \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24333-x","DOIUrl":"10.1007/s10409-024-24333-x","url":null,"abstract":"<div><p>Ceramic matrix composites have broad application prospects in the aerospace field due to their high temperature resistance and oxidation resistance. The effect of temperature and environment atmosphere on the fracture toughness and failure mechanisms of two-dimensional plain-woven SiC_f/SiC composites was investigated. The results show that they exhibit pseudo-plastic deformation behavior at different temperatures. The fracture toughness is as high as 48 MPa m^1/2 at room temperature, and gradually decreases with rising temperature. The difference in fracture toughness between argon and air initially increases and then decreases with rising temperature. Furthermore, the high-temperature failure mechanisms of these composites were analyzed through macro and micro analysis. Based on this, a physic-based temperature-dependent fracture toughness model considering matrix toughness, plastic power, fiber pull-out, and residual thermal stress was developed for fiber-reinforced ceramic matrix composites. The model has been well validated by experimental results. An analysis of influencing factors regarding the evolution of fracture toughness was conducted by the proposed model. This work contributes to a better understanding of the mechanical performance evolution and failure mechanisms of ceramic matrix composites under multi-field coupling conditions, thereby promoting their applications.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143570992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correction to: Time-dependent viscoelastic behavior of an LDPE melt","authors":"Shuxin Huang,&nbsp;Yurun Fan","doi":"10.1007/s10409-024-24900-x","DOIUrl":"10.1007/s10409-024-24900-x","url":null,"abstract":"","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 3","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomistic study on the effects of short-range order on the creep behavior of TiVTaNb refractory high-entropy alloy at high temperature","authors":"Zhong-Ao Zhang \u0000 (,&nbsp;),&nbsp;Yan-Kun Dou \u0000 (,&nbsp;),&nbsp;Xin-Fu He \u0000 (,&nbsp;),&nbsp;Yong-Peng Zhao \u0000 (,&nbsp;),&nbsp;Wen-Jia Jiang \u0000 (,&nbsp;),&nbsp;Wen Yang \u0000 (,&nbsp;)","doi":"10.1007/s10409-024-24478-x","DOIUrl":"10.1007/s10409-024-24478-x","url":null,"abstract":"<div><p>Creep is an important mechanical property of refractory high-entropy alloys (RHEAs) at high temperatures. The existence of short-range order (SRO) and its ability to improve the strength or plasticity of high-entropy alloys (HEAs) have been experimentally proven. However, there is still little research on the correlation between SRO and creep behavior. The mechanism of SRO influencing creep behavior is not yet clear. In this work, the creep behaviors of TiVTaNb RHEA with and without SRO were simulated at various temperatures and stresses using molecular dynamics methods, and the effects of SRO on creep behavior were analyzed. The results show that the SRO is energetically favorable for occurrence in this RHEA. For polycrystalline RHEAs, grain boundary energy is an important driving force for the formation of SRO. Significantly, under the same conditions, the SRO can reduce the steady-state creep rate and change the creep mechanism of the RHEA. Specifically, the models with SRO will exhibit lower stress exponent and grain-size exponent. A mechanism by which SRO reduces the effects of grain boundaries on creep has been discovered. These phenomena can be well explained by the effects of SRO on atomic diffusion. In addition, by analyzing the diffusion ability of different elements, SRO can induce localization of atomic diffusion, resulting in strain localization under high stresses. This work highlights the importance of SRO on the creep of RHEAs and provides a reference for establishing a reasonable creep model of RHEAs.</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7109,"journal":{"name":"Acta Mechanica Sinica","volume":"41 12","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}