检索结果-内蒙古大学图书馆

Accurately and automatically simulating hysteresis loops of shape memory alloys

CONTINUUM MECHANICS AND THERMODYNAMICS 2022年第3期34卷 739-761页

作者： Wang, Si-Yu Zhan, Lin Bruhns, Otto T. Xiao, Heng Jinan Univ Coll Mech & Construct Engn MOE Key Lab Disaster Forecast & Control Engn West Huangpu Ave 601 Guangzhou 510632 Peoples R China Zhejian Univ Coll Aerosp & Aeronaut Engn Hangzhou 310058 Peoples R China Ruhr Univ Bochum Inst Mech D-44780 Bochum Germany

Toward directly simulating pseudo-elastic effects of shape memory alloys, new elastoplastic equations of von Mises type are proposed by correlating the yield surface radius with the yield surface center, thus establishing a new elastoplasticity model characterized by three coupled quantities for isotropic and anisotropic hardening. Within the framework of conventional macroscopic elastoplasticity, it is demonstrated that the new model can exactly reproduce pseudo-elastic hysteresis effects of shape memory alloys, with no need to characterize any microstructural features of solid-solid phase transitions. To this end, explicit expressions for the three hardening quantities introduced are presented in terms of two single-variable functions. Then, exact closed-form solutions are obtained for the uniaxial stress-strain responses in a loading and a subsequent unloading process, and such responses are shown to give rise to a hysteresis loop shaped just by the foregoing two single-variable functions. As such, hysteresis loops of arbitrary shapes can be simulated in a straightforward and accurate manner simply prescribing two single-variable functions shaping such loops. For the first time, cumbersome and time-consuming procedures both for conducting statistical averaging schemes and for identifying numerous unknown parameters may be bypassed with broad applicability.

关键词： Shape memory alloys Pseudo-elasticity Finite strain Elastoplastic equations Combined hardening

来源：评论

学校读者我要写书评

暂无评论

Flow behavior of laval nozzle sets in steam turbine governing stage at low loads

引用

THERMAL SCIENCE AND engineering PROGRESS 2023年 46卷

作者： Gan, Yiming Huang, Chang Wang, Weiliang Jinan Univ Energy & Elect Res Ctr Zhuhai 519070 Peoples R China Jinan Univ MOE Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Peoples R China

To achieve carbon neutrality, thermal power units (TPU) will be deeply involved in peak regulation, which is crucial for the development of renewable energy generation. However, the efficiency of TPU is significantly reduced at low loads. The main reason for this is that the convergent nozzles in conventional TPU are difficult to efficiently expand steam with large pressure differentials (i.e., pressure ratios below a critical value), and thus the unit is designed to operate in sliding-pressure mode, resulting in a low Rankine cycle efficiency. To reveal the mechanism of energy loss in the governing stage under peak shaving conditions, the flowing behavior of governing stage nozzle sets of a 330 MW steam turbine is investigated by CFD simulation in this study. The results indicated that the shock waves generated by the supercritical streamflow and the angle deviation at the exit of nozzle sets are the main factors leading to energy efficiency degradation. Based on this, two supersonic Laval nozzles were designed and analyzed in the 10 %similar to 40 % load range. Compared with conventional nozzles, the designed supersonic nozzles I and II showed average efficiency improvements of 4.9 % and 5.8 %, respectively, and maximum efficiencies of 6.6 % and 9.5 %, respectively. The research in this paper can provide theoretical support for the design and development of nozzle sets under deep peaking conditions, which can help achieve carbon neutrality.

关键词： Supersonic Laval nozzles Flow behavior Governing stage Carbon neutrality CFD simulation

来源：评论

学校读者我要写书评

暂无评论

Constitutive models of constrained concrete in cross-shaped PEC column under axial compression

引用

JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH 2024年 215卷

作者： Li, Guofei Li, Yuanping Jinan Univ Sch Mech & Construct Engn Guangzhou 510632 Guangdong Peoples R China Jinan Univ Key Lab Disaster Forecast & Control Engn Minist Educ Peoples Republ China Guangzhou 510632 Guangdong Peoples R China

Based on the influence of lateral constraints, there are two categories of constraint areas within a cross-shaped partially encased composite (CPEC) column: strong constraint areas (SCAs) and weak constraint areas (WCAs). Due to the diverse constraint effects of profile steel on concrete, dissimilar stress-strain constitutive models are exhibited by SCA and WCA, and they contribute differently to the bearing capacity of columns. Based on the constraint mechanism of the CPEC column, the methodologies for partitioning the constraint areas and determining effective constraint coefficients and strength enhancement coefficients of concrete are proposed to establish the constitutive model of constrained concrete. A formula that accounts for the constraint effect is proposed for estimating the axial compressive ultimate capacity of CPEC columns based on the limit equilibrium method. The study demonstrates that the strength of concrete in SCA is significantly enhanced compared with unconstrained concrete, resulting in an increased bearing capacity. The calculated axial load-displacement curves of columns using the derived constrained concrete constitutive models in this study are in good agreement with experimental results. The derived axial compressive ultimate bearing capacity formula quantifies the constraint effect of concrete with high computational accuracy.

关键词： CPEC column Constrained concrete Stress-strain constitutive model Limit equilibrium method Axial compressive ultimate bearing capacity

来源：评论

学校读者我要写书评

暂无评论

Exact large strain analysis for the Poynting effect of freely twisted thin-walled tubes made of highly elastic soft materials

引用

THIN-WALLED STRUCTURES 2023年第1期184卷

作者： Han, Meng-Liang Wang, Hui-Yu Wang, Si-Yu Xiao, Heng Jinan Univ Sch Mech & Construct Engn Guangzhou 510632 Peoples R China Jinan Univ MOE Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Peoples R China

Toward handling nonlinear coupling effects at large elastic deformations, a decoupled form of the multi-axial elastic potential for highly elastic soft materials is first constructed based on Hencky's logarithmic strain, and this new potential is then used to obtain analytic results for the uniaxial extension and compression of a bar, the equi-biaxial extension of a plate, the plane-strain extension of a strip and, in particular, the large torsion of a thin-walled tube with free ends. Novelties are included in the following three respects: (a) Experimental data for responses of the uniaxial extension, equi-biaxial extension (uniaxial compression) and plane-strain extension (simple shear) may be accurately matched up to large strain with strain-stiffening effects;(b) exact responses for the Poynting effect of freely twisted thin-walled tubes may be derived for changes in the axial length and the wall thickness as well as the averaged radius;and (c) the coupling nonlinear complexities involved in all such responses may be worked out in a decoupled sense.

关键词： Soft materials Highly elastic Thin-walled tube Large free torsion Decoupled approach

来源：评论

学校读者我要写书评

暂无评论

Study on parameter measurement of elastic thin films with substrate effect based on contact mechanics

引用

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES 2023年第1期271卷

作者： Zhang, Wen-Hua Jinan Univ MOE Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Peoples R China Jinan Univ Sch Mech & Construct Engn Guangzhou 510632 Peoples R China

The development of contact theories for films is valuable for high-precision machining and measurement. Accordingly, accurate contact mechanics theories for films under common indenter loading are established based on the constitutive equations and potential theory method, Here, the film structures are "film with two free boundaries" and "film/rigid substrate." The displacement and stress at arbitrary positions can be obtained using exact solutions represented by elementary functions. The application of the foregoing theories to resolve the contact problem encountered in films is convenient for engineers. The influences of substrate and film parameters on contact radius and indentation depth were analyzed. Indentation curves are slightly influenced by Poisson's ratio, but primarily affected by the elastic modulus. An effective method for measuring of film material parameters is presented. Using numerical software platforms, the method's analytic algorithm can be transformed into numerical codes and be integrated into special software.

关键词： Film Spherical contact Conical contact Cylindrical contact Mirror image method Substrate effect Measurement

来源：评论

学校读者我要写书评

暂无评论

Debonding Analysis of Adhesively Bonded Pipe Joints Subjected to Combined Thermal and Mechanical Loadings

引用

INTERNATIONAL JOURNAL OF COMPUTATIONAL METHODS 2022年第6期19卷

作者： Yuan, Hong Han, Jun Zhang, Huanliang Zeng, Lan Jinan Univ Sch Mech & Construct Engn MOE Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Peoples R China

In order to better understand the interfacial debonding behavior of pipe joints during the whole loading process, an analytical solution for the full-range behavior of adhesively bonded pipe joints under combined thermal and mechanical tensile loadings is presented in this paper. The solution was developed based on a simplified rigid-softening bond-slip model, and two cases with different softening region development were discussed. The analytical results were presented in a finite element model, and the effect of temperature on load-displacement curves and ultimate loads was shown based on the model. Through the nonlinear fracture mechanics, the analytical expressions of the interfacial shear stress and the load-displacement relationship can be obtained. The stress transfer mechanism, the interface crack propagation and the ductility behavior of the joints can be explained. This analytical result can help improve the potential application of fabricated structural components, precision instruments, oil and gas pipelines.

关键词： Pipe joints interfacial debonding thermal and mechanical coupling bond-slip model finite element model

来源：评论

学校读者我要写书评

暂无评论

Nonlinear eccentric bending and buckling of laminated cantilever beams actuated by embedded pre-stretched SMA wires

引用

COMPOSITE STRUCTURES 2022年 284卷

作者： Jin, Fusong Zhao, Chen Xu, Peng Xue, Jianghong Xia, Fei Jinan Univ Sch Mech & Construct Engn MOE Key Lab Disaster Forecast & Control Engn Guangzhou 510632 Peoples R China

This paper presents a theoretical approach to analyze the eccentric bending and buckling of laminated cantilever beams actuated by embedded pre-stretched SMA wires. Two mechanisms are involved: phase transition of the SMA wires and the nonlinear bending of the laminated beam. On the basis of material model for shape memory alloy during the phase transition in thermal field proposed by Brison, constitutive relations of the SMA hybrid laminated beams are established to interpret the relationship among the recovery stress, the internal stress, the thermal temperature and the thermal expansion. Governing equations in terms of the slope function and the horizontal displacement are derived according to von-Kaman geometrically nonlinear relationships. The nonlinear bending deformation of the SMA hybrid laminated beams is analyzed by considering the deflection due to eccentric bending moment as an initial imperfection and is solved using perturbation approach. A compatible condition is proposed to ensure consistent deformation between the SMA wires and the laminated beams. By developing Matlab program, parametric studies are carried out to investigate the effect of the pre-strain, the volume fraction and the location of the SMA wires on the deflection, the critical temperature, the recovery stress and the internal stress of the SMA hybrid laminated beams. The efficiency and accuracy of the analytical solutions were expounded by comparing with the results from finite element analysis. It is found that buckling may or may not occur in the SMA hybrid laminated beam relying on the value of the pre-strain of the SMA wires.

关键词： SMAHC von-Kaman nonlinear relationships Recovery stress Buckling Critical temperature

来源：评论

学校读者我要写书评

暂无评论

Failure Analyses of Cylindrical Lithium-Ion Batteries Under Dynamic Loading Based on Detailed Computational Model

引用

ACTA MECHANICA SOLIDA SINICA 2025年 1-13页

作者： Xi, Huifeng Zhao, Guicheng Wang, Shuo Li, Junkui He, Linghui Yang, Bao Jinan Univ Sch Mech & Construct Engn 601 West Huangpu Ave Guangzhou 510632 Peoples R China Jinan Univ Lab Disaster Forecast & Control Engn MOE West Huangpu Ave 601 Guangzhou 510632 Peoples R China Doctor Workstat Xuwen Cty Guangdong Hydropower Ene 207 Natl Highway Xuwen 524100 Peoples R China Univ Sci & Technol China CAS Key Lab Mech Behav & Design Mat Hefei 230026 Peoples R China South China Univ Technol Sch Civil Engn & Transportat Guangzhou 510640 Peoples R China

Electric vehicles, powered by electricity stored in a battery pack, are developing rapidly due to the rapid development of energy storage and the related motor systems being environmentally friendly. However, thermal runaway is the key scientific problem in battery safety research, which can cause fire and even lead to battery explosion under impact loading. In this work, a detailed computational model simulating the mechanical deformation and predicting the short-circuit onset of the 18,650 cylindrical battery is established. The detailed computational model, including the anode, cathode, separator, winding, and battery casing, is then developed under the indentation condition. The failure criteria are subsequently established based on the force-displacement curve and the separator failure. Two methods for improving the anti-short circuit ability are proposed. Results show the three causes of the short circuit and the failure sequence of components and reveal the reason why the fire is more serious under dynamic loading than under quasi-static loading.

关键词： 18,650 lithium-ion battery Detailed computational model Deformation Fracture mode Failure criteria

来源：评论

学校读者我要写书评

暂无评论

Free vibration of non-shallow, laminated cylinders submerged in a fluid with general boundary conditions

引用

APPLIED OCEAN RESEARCH 2022年 125卷

作者： Yao, Sishi Zhang, Yaqian Xue, Jianghong Jin, Fusong He, Zanhang Jinan Univ Sch Mech & Construction Engn Key Lab Disaster Forecast & Control Engn MOE Guangzhou 510632 Peoples R China

This paper presents a theoretical approach to analyze the free vibration of laminated cylinders with general boundary conditions submerged in a fluid. Based on the assumption that the fluid is inviscid, irrotational and incompressible, the equation of motion of the fluid is established. Fluid-structure interaction between the cylinder and the fluid is conducted by satisfying the continuity conditions of the force and of the vibration velocity at the interfaces of the cylinder and the fluid. The curvature-deflection relations are modified to include the effect of the initial curvatures in the circumferential direction of the non-shallow shell. According to the mechanics of composite materials, governing equations for the cylinder undergoing out-of-plane vibration are derived and are solved using Rayleigh-Ritz method. Likely functions of the displacements for cylinders with general boundary conditions are proposed. Furthermore, finite element simulations are fulfilled using ABAQUS. A good agreement between the analytical solutions and finite element results illustrates the efficiency and accuracy of the proposed approach. With the established models, the influence of the slenderness ratio, radius thickness ratio, the material properties and the fluid-structure interaction on the vibration performance of the laminated cylinder submerged in the fluid is evaluated.

关键词： Laminated composites Fluid-structure interaction Non-shallow cylindrical shells Free vibration Rayleigh-Ritz method

来源：评论

学校读者我要写书评

暂无评论

Bending fatigue of single-wall and double-wall corrugated paperboards under sinusoidal and random loads

引用

JOURNAL OF SANDWICH STRUCTURES & MATERIALS 2022年第2期24卷 1004-1027页

作者： Wang, Zhi-Wei Lai, Yang-Zhou Wang, Li-Jun Jinan Univ Packaging Engn Inst Zhuhai 519070 Peoples R China Jinan Univ Sch Mech & Construct Engn MOE Key Lab Disaster Forecast & Control Engn Guangzhou Peoples R China Jinan Univ Key Lab Prod Packaging & Logist Guangdong Higher Zhuhai Peoples R China Jinan Univ Zhuhai Key Lab Prod Packaging & Logist Zhuhai Peoples R China Tianjin Univ Sci & Technol Coll Light Ind Sci & Engn Tianjin Peoples R China

The bending fatigue tests of single-wall and double-wall corrugated paperboards were conducted to obtain the epsilon(rms)-N curves under sinusoidal and random loads in this paper. The epsilon(rms)-N equation of corrugated paperboard can be described by modified Coffin- Manson model considering the effect of mean stress. Four independent fatigue parameters are obtained for single-wall and double-wall corrugated paperboards. The epsilon(rms)-N curve under random load moves left and rotates clockwise compared with that under sinusoidal load. The fatigue life under random load is much less than that under sinusoidal load, and the fatigue design of corrugated box should be based on the fatigue result under random load. The stiffness degradation and energy dissipation of doublewall corrugated paperboard before approaching fatigue failure are very different from that of single-wall one. For double-wall corrugated paperboard, two turning points occur in the stiffness degradation, and fluctuation occurs in the energy dissipation. Different from metal materials, the bending fatigue failure of corrugated paperboard is a process of wrinkle forming, spreading, and folding. The results obtained have practical values for the design of vibration fatigue of corrugated box.

关键词： Bending fatigue corrugated paperboard epsilon(rms)-N curves residual stiffness energy dissipation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：