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1.
JIANG Wugui FU Mingfu CHEN Liangsen GENG Shiqi Department of Materials Science Engineering Nanchang Institute of Aeronautical Technology Nanchang Jiangxi P.R. China Institute of Engineering Mechanics Nanchang University Nanchang Jiang 《重庆大学学报(英文版)》2004,3(1):78-81
~~6.ConclusionsJaumannsrate,FusrateandWusratewereincorporatedintotheendochronicequationstoanalyzesimpleshearfinitedeformation.Incrementalequationsandnumericalsolutionsarepresentedforthreeendo-chronicobjectivemodels.TheresultsshowthatanoscillatoryshearstressresponsetoamonotonicallyincreasingshearstrainoccurswhentheJaumannsrateobjectivemodelisemployedforendochronicmaterials.Theoscillatoryresponseisdependentontheadoptedobjectiverate.ComparedwiththeJaumannsrate,theFusrateandtheWusratesatisfythe… 相似文献
2.
振动剪切作用下LDPE和HDPE熔体的非仿射网络结构模型 总被引：1，自引：0，他引：1
We propose molten polymer‘s entanglement network deformation to be nonaffine and use transient network structural theory with the revised Liu‘s kinetics rate equation and the revised upper convected Maxwell constitutive equation to establish a nonaffine network Structural constitutive model for studying the rheological behavior of molten Low-Density Polyethylene(LDPE)and High Density Polyethylene(HDPE)in oscillatory shear.As a result,when the strain amplitude or frequency increases,the shear stress amplitude increases.At the same time,the accuracy of the nonaffine network model is higher than that of affine network model.It is clear that there is a small amount of nonaffine network deformation for LDPE melts which have long-chain branches,and there is a larger amount of nonaffine network deformation in oscillatory shear for HDPE melts which has no long-chain branches.So we had better consider the network deformation nonaffine when we establish the constitutive equations of polymer melts in oscillatory shear. 相似文献
3.
Knitted fabric is very different from woven fabric due to its more complicated knitting structures. The buckling of knitted fabric sheets subjected to simple shear in the wale direction is investigated analytically in consideration of the large deformation of fabric sheet in critical configuration. The theory on instability of finite deformation is applied to the analysis. All the stress boundary conditions of knitted fabric sheet are satisfied. An equation to determine the buckling direction angle is derived. It is shown that there are two possible buckling modes, flexural mode and barreling mode. The buckling condition equations for the flexural mode and barreling mode are also obtained respectively. Numerical illustrations reveal that only the flexural mode can actually occur and the barreling mode cannot, which agrees with the experimental observations. For a permitted buckling mode on margin boundaries, the critical value of shear amount and the buckling direction angle can be determined. 相似文献
4.
In this paper, a nonlinear mathematical model for analyzing dynamical response to the large deformation of piles with initial displacements is firstly established with the arc-coordinate, and it is a set of nonlinear integral-differential equations, in which, the Winkeler model is used to simulate the resistance of the soil to the pile. Secondly, a set of new auxiliary functions are introduced. The differential-integral equations are transformed into a set of nonlinear differential equations,and the differential quadrature method (DQM) and the finite difference method (FDM) are applied to discretize the set of nonlinear equations in the spatial and time domains, respectively. Then, the Newton-Raphson method is used to solve the set of discretization algebraic equations at each time step. Finally, numerical examples are presented, and the dynamical responses to the deformation of piles, including configuration, bending moment and shear force, are graphically illuminated. In calculation, two types of initial displacements and dynamical loads are applied, and the effects of parameters on the dynamical responses of piles are analyzed in detail. 相似文献
5.
丁启阵先生在<杜甫、严武"睚眦"考辨>一文中引用了大量杜诗来证明杜甫、严武之间发生过"睚眦",然而对于所引杜诗如<哭严仆射归榇>等分析多不够客观,尚需重新解读;且最能说明杜甫、严武之间关系深厚的<八哀诗·赠左仆射郑国公严公武>和<诸将五首>其五,丁文却都没有全篇引用并加以解析,难免有隐匿反证之嫌. 相似文献
6.
The effect of axial shallow groove on the nonlinear dynamic response and buckling of laminated cylindrical shells subjected to radial compression loading was investigated. Based on the first-order shear deformation theory （FSDT）, the nonlinear dynamic equations involving the transverse shear deformation and initial geometric imperfections were derived with the Hamilton philosophy. The axial shallow groove of the laminated composite cylindrical shell was treated as the initial geometric imperfections in the dynamic equations. A semi-analytical method of expanding displacements and loads along the circumferential direction and employing the finite difference method along the axial direction and in the time domain is used to solve the governing equations and obtain the dynamic response of the laminated shell. The B-R criterion was employed to determine the critical loads of dynamic buckling of the shell. The effects of the parameters of the shallow groove on the dynamic response and buckling were discussed in this paper and the results show that the axial shallow grooves greatly affect the dynamic response and buckling. 相似文献
7.
TANG Qian ZHU Cai-chao LIAO Xiao-yun LU Bo 《重庆大学学报(英文版)》2005,4(3):125-128
Traditional variation analysis methods are not applicable to non-rigid assemblies due to possible part deformation during the assembly process. This paper presents the use of finite element methods to simulate assembly deformation. The relationship between the parts＇ variation and the variation of the key points in final assembly for quality control is set up by calculating the spring back deformation after assembly. Moreover, the optimization method for non-rigid assembly variations based on finite element analysis is presented. The optimal objective is to reduce the manufacturing cost. The approach is implemented by using ANSYS and MATLAB. The test example shows that the proposed method is effective and applicable. 相似文献
8.
Theoretical Calculation and Analysis of Slip and Deformation for Concrete Sandwich Panels 总被引：1，自引：0，他引：1
Slip and deformation of concrete sandwich panels under uniformly distributed loads is concerned. The effect of slip on the deformation of concrete sandwich panels are studied,and the analytical expressions of slip and deformation for concrete sandwich panels is obtained. These formulae can describe the slip distribution and account for its effect on deformation. In order to restrict the bound of formula, the formula of crack moment is obtained. The results of theoretical calculation are compared with those of tests and finite element methods. The comparison shows that the results of theoretical calculation are in accord with those of tests and finite element methods. So the theoretical calculation can be used to calculate slip and deformation of concrete sandwich panels in practical projects. 相似文献
9.
考虑剪切效应有限变形粘弹性板的动力稳定性 总被引：4，自引：0，他引：4
Based on Reddy‘s theory of plates with higher-order shear deformations and the Boltzmann superposition principles,the governing equations were established for dynamic stability of viscoelastic plates with finite deformations taking account of shear effects,The Galerkin method was applied to simplify the set of equations.The numerical methods in nonlinear dynamics were used to solve the simplified system.It could e seen that there are plenty of dynamic properties for this kind of viscoelastic plates under transverse harmonic loads.The influences of the transverse shear deformations and material parameter on the dynamic behavior of nonlinear viscoelatic plates were investigated. 相似文献
10.
基于DEFORM-3D有限元分析软件,采用刚黏塑性热力耦合有限元模拟技术,对4032铝合金销轴热挤压成形过程进行了模拟与分析,获得了金属流动、挤压载荷、等效应变以及坯料内部温度等相关场量的变化规律。结果表明：4032铝合金销轴热挤压变形时,坯料心部金属的流动速度大于表层金属;内部变形可分为4个区域,即未变形区、变形区、已变形区和死区;坯料在凹模模口附近变形最为剧烈,挤压载荷急剧增加,等效应变梯度最大,局部温升明显。 相似文献
11.
O形密封圈的非线性有限元分析 总被引：1，自引：0，他引：1
利用大型有限元分析软件ANSYS，考察了橡胶O形圈的大变形引起的几何非线性和接触非线性，建立了橡胶O形圈和沟槽接触的轴对称非线性有限元分析模型，分析了橡胶O形圈在安装使用中，其沟槽内的接触情况和橡胶O形圈内应力的分布规律，为橡胶密封件的设计开辟了一条新方法。从而为进一步可靠设计、优化橡胶O形圈提供了理论依据。 相似文献
12.
INTRODUCTION Piezoelectric bimorphs (or benders), a special type of piezoelectric device, which can produce flexural deformation significantly larger than the length or thickness deformation of the individual piezoelectric layers, have been widely used as elec- troacoustic transducers, medical devices and micro- robot due to their characteristics of easy miniaturiza- tion, high positioning accuracy, sensitive response, and large displacement (e.g., Shirley and Hampton, 1978; Ha and Kim, 2… 相似文献
13.
硬盘系统一般采用气体润滑，以提高使用寿命和读写可靠性．本文讨论了多聚脂流体润滑的ＩＢＭ３３７０ 磁头／ 磁盘系统，以期提高磁记录密度．润滑模型中考虑了超薄流体润滑的剪薄效应，并用有限差分法对润滑方程进行求解．应用摄动理论建立了ＩＢＭ３３７０ 磁头／ 磁盘系统的动力学模型，分别对气体润滑和液体润滑的两自由度磁头的动力响应进行了仿真．仿真结果表明，在相同磁头倾角条件下，液膜润滑的磁头／ 磁盘的动力稳定性优于气体润滑的磁头／ 磁盘系统 相似文献
14.
孙翠兰 《河北工业大学成人教育学院学报》2007,22(4):49-52,62
轻钢骨混凝土结构是一种新型的结构体系,它自重轻,安装方便,保温性能好,因而有广阔的发展余地和使用空间。本文分别对轻钢骨模网混凝土的工作性能、轻钢骨剪力墙的抗剪性能做了深入的理论研究。用3片缩尺轻钢骨剪力墙模型进行了试验研究,并推导了轻钢骨剪力墙的抗剪承载力公式。由于模型试验构件少,数据有所不足,本文又采用ADINA有限元分析软件进行分析,提出有关轻钢骨砼剪力墙轴压比设计的建议。 相似文献
15.
The analyses of finite deformation and stress for a hyperelastic rectangular plate with some voids under an uniaxial extension were conducted. The governing differential equations were given from the incompressibility condition of the material. The solution was approximately obtained from the minimum potential energy principle. The growth of voids was discussed. One can see that an initial central circular-cylinder void becomes an elliptic-cylinder void, but an initial non-centeral circular-cylinder void becomes an elliptic-like cylinder void and the center of void has a shift. The stress distributions along the edges of voids were given and the phenomenon of stress concentration was observed. The influences of the distribution manner and size of voids, as well as the distance between them on the growth of voids were analyzed. 相似文献
16.
蜂窝结构抗剪性能实验研究及其数值模拟 总被引：2，自引：0，他引：2
蜂窝结构以优异的力学性能,如比刚度大、比强度大、重量轻、良好的隔音隔热等,在建筑、工业锅炉、航空等结构中得到广泛的应用。抗剪性能是蜂窝结构主要力学性能之一,本文利用剪切实验和四点弯曲实验对PVC材料的圆形错排蜂窝结构的等效剪切模量及抗剪强度进行了实验研究,并利用有限元软件ANSYS对两种实验进行了三维有限元数值模拟。两种实验测得的等效剪切模量结果和数值模拟结果比较吻合。结果表明可以通过数值模拟对蜂窝结构的力学性能参数进行估算,并通过数值模拟为实验设计和工程实际设计理论依据和指导。 相似文献
17.
通过大型有限元软件ANSYS对带刚性连梁的双肢短肢剪力够结构的刚度以及混凝土的非线性进行计算和分析。结果显示:设置刚性连粱可以有效地增强短肢剪力墙结构的侧移刚度,同时具有较好的延性性能。 相似文献
18.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｎｏｎｃｏｎｆｏｒｍｉｎｇｆｉｎｉｔｅｅｌｅｍｅｎｔＱ6(Ｗｉｌｓｏｎｅｔａｌ.,1 973)ｉｍｐｒｏｖｅｓｔｈｅａｃｃｕｒａｃｙｏｆｃｏｎｆｏｒｍ ｉｎｇｆｉｎｉｔｅｅｌｅｍｅｎｔＱ4ｂｙｉｎｃｏｒｐｏｒａｔｉｎｇｈｉｇｈｅｒｏｒ ｄｅｒｎｏｎｃｏｎｆｏｒｍｉｎｇｄｉｓｐｌａｃｅｍｅｎｔｓｗｈｉｃｈｒｅｄｕｃｅｔｈｅｓｈｅａｒｌｏｃｋｉｎｇ,ｓｏｆｔｅｎｔｈｅｓｔｉｆｆｎｅｓｓｏｆｃｏｍｐａｔｉ ｂｌｅｅｌｅｍｅｎｔｓａｎｄｉｎｃｒｅａｓｅｔｈｅｉｎｔｅｒｐｏｌａｔｉｏｎａｃ… 相似文献
19.
双层钢板混凝土组合剪力墙的抗剪性能(英文) 总被引：1，自引：0，他引：1
为深入了解双层钢板混凝土组合剪力墙的抗剪性能,采用数值模拟的方法研究了钢板厚度、混凝土厚度、混凝土强度及组合剪力墙的跨高比等主要参数对该组合剪力墙抗剪性能的影响规律,并提出了该组合剪力墙弹性抗侧刚度及抗剪极限承载力的简化计算公式.研究表明:随着钢板厚度、混凝土厚度、混凝土强度等级的增加,组合剪力墙的抗剪性能均有较显著的提高;组合剪力墙跨高比的变化对其弹性抗侧刚度影响较大,而对其抗剪极限承载力的影响并不明显.通过将公式计算结果与有限元计算结果进行对比分析,发现提出的简化计算公式较合理,能较好地反映双层钢板混凝土组合剪力墙的实际受力状态.该结论可作为双层钢板混凝土组合剪力墙初步设计的参考建议. 相似文献
20.
The finite deformation and stress analyses for a rectangular plate with a center void and center void and made of rubber with the Yeoh elastic strain energy function under uniaxial extension were studied in this paper.An approximation solution was botained from the minimum potential energy principle.The num,erical results for the growth of the cavitation and stresses along the edge of the cavitation were discussed.In addition,the stress concentration phenomenon was considered. 相似文献