共查询到18条相似文献,搜索用时 187 毫秒
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各向异性板半无限裂纹平面问题的保角变换解法 总被引:1,自引:0,他引:1
本文给出了各向异性板半无限裂纹平面问题的保角变换解.首先,简单介绍了各向异性板平面问题的基本理论.随后采用复变函数的方法,通过引用适当的保角映射研究了各向异性板半无限裂纹平面弹性问题,得到了各向异性板中半无限裂纹在任意面内集中载荷作用下的裂纹尖端的应力强度因子的解析解.最后,作为特例得到了当集中力作用在裂纹表面时的应力强度因子的解析解,依此验证了结果的正确性.结果表明该方法简单实用. 相似文献
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本文在von Kármán型板理论的基础上,采用双重Fourier级数方法,研究了对称正交层合矩形板在简支边条件下,承受任意分布横向载荷和面内载荷联合作用的非线性弯曲问题,得到了满足控制方程和边界条件的解. 相似文献
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从正交各向异性压电介质平面问题,对于材料3个特征根互不相等情况下,以3个拟调和位移函数表达位移、电势、应力和电位移的通解出发,利用调和多项式的显式表达式,结合试凑法,给出了平面压电梁的若干典型问题的解析解,包括悬臂压电梁自由端作用横向集中力和点电荷,悬臂压电梁表面作用线性电势和均布载荷,以及两端简支压电梁作用均布载荷等的解析解. 相似文献
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任意厚度具有自由边叠层板的精确解析解 总被引:1,自引:0,他引:1
自由边问题一直是三维弹性力学中的难题,通常很难满足自由边上一个正应力和两个剪应力都等于0.基于三维弹性力学基本方程和状态空间方法,引入自由边界位移函数并考虑全部弹性常数,建立了正交异性具有自由边单层和叠层板的状态方程.对状态方程中的变量以级数形式展开,通过边界条件的满足精确求解任意厚度具有自由边叠层板的位移和应力,此解满足层间应力和位移的连续条件.算例计算表明,采用引入的位移函数形式,简化了计算过程并且采用较少的级数项可以获得收敛解.与有限元方法计算结果进行了对比,可以得到较高精度的数值结果.其解可以作为其它数值方法和半解析方法的参考解. 相似文献
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复合材料桥纤维拔出问题的动态裂纹模型 总被引:2,自引:1,他引:1
在一无限的正交各向异性体的弹性平面上,对具有桥纤维平行自由表面的一个内部中央裂纹,进行了弹性分析.提出了复合材料桥纤维拔出的一个动态模型.由于纤维破坏是由最大拉应力支配,纤维断裂并且裂纹扩展将以自相似的方式出现.通过复变函数的方法将所讨论的问题转化为Reimann-Hilbert混合边界值问题的动态模型,呈现一简单的和容易的解.求得了正交异性体中扩展裂纹受运动的阶梯载荷、瞬时脉冲载荷作用下问题的解析解,并利用这一解,通过迭加最终求得该模型的解. 相似文献
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本文在阶梯折算法的基础上,提出一个新的方法——精确解析法,得到了非均匀弹性地基圆板弯曲的一般解.文中导出了在任意轴对称载荷和边界条件下求解非均匀弹性地基圆板和中心带孔圆板弯曲的一般公式,并给出一致收敛于精确解的证明.文中得到的一般解可直接计算无弹性地基圆板的弯曲问题.问题最后归结为求解一个二元一次代数方程.文末给出算例,算例表明无论内力和位移均可得到满意的结果. 相似文献
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A solution for the elastic and inelastic local buckling of flat rectangular plates with centerline boundary conditions subjected to non-uniform in-plane compression and shear stress is presented. The loaded edges are simply supported, the longitudinal edges may have any boundary conditions and the centerline is simply supported with a variable rotational stiffness. The Galerkin method, an effective method for solving differential equations, is applied to establish an eigenvalue problem. In order to obtain plate buckling coefficients, combined trigonometric and polynomial functions that satisfy the boundary conditions are used. The method is programmed, and several numerical examples including elastic and inelastic local buckling, are presented to illustrate the scope and efficacy of the procedure. The variation of buckling coefficients with aspect ratio is presented for various stress gradient ratios. The solution is applicable to stiffened plates and the flange of the I-shaped beams that are subjected to biaxial bending or combined flexure and torsion and shear stresses, and is important to estimate the reduction in elastic buckling capacity due to stress gradient. 相似文献
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Summary The stress distribution obtained by solving the two-dimensional problem in an anisotropic medium, with boundary conditions of a concentrated tangential load acting on the boundary of a semi-infinite plate, is purely radial. The solution is given in closed form and is combined with the solution for a concentrated normal load to solve the problem of an inclined force acting on the boundary. 相似文献
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Reissner厚板弹性弯曲的一般解析解 总被引:6,自引:2,他引:4
针对大型工程建设中的Reisner厚板弹性弯曲问题,本文采用复级数方法求解相应的常系数偏微分方程组的边值问题,并首次得到了任意边界条件下的一般解析解.该解形式简单,计算方便、可靠.以四边简支和三边固支一边自由两种支撑条件下厚板承受均布载荷为例进行了分析验算,与已有的计算结果相比,计算结果相当满意.同时本文还着重对解的收敛速度、正确性(合理性)及边界满足情况进行了考察. 相似文献
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弹性地基上自由边矩形厚板的分栀由于其难度较大,一直没有得到很好的解决.本文采用单三角级数和重三角级数相叠加的方法,求得该问题的精确解.文中所用方法简单明了.所得结果完全满足边界条件并与王克林等[2]的结果完全一致. 相似文献
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复合材料层合板的三维非线性分析 总被引:5,自引:1,他引:4
本文提出了一种研究复合材料层合板壳三维问题的解析方法.该方法采用摄动方法和变分原理来满足三维弹性理论基本微分方程及限制条件,分析了受横向载荷作用的复合材料各向异性单层圆板及层合圆板的三维非线性问题.得到了高精确度的摄动级数解答.大量结果表明横向剪应力和横向正应力在层合板的三维非线性分析中是很重要的. 相似文献
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O. N. Demchouk 《Mechanics of Composite Materials》1998,34(3):253-262
An uncoupled dynamic thermoelastic problem for laminated composite plates has been considered. The hypotheses used take into account the nonlinear distribution of temperature and displacements over the thickness of a laminated plate. On the basis of these hypotheses a quasi-three-dimensional (layerwise) theory is constructed that makes it possible to investigate the internal thermal and stress-strain states, as well as the edge effects of the boundary layer type for laminated plates. Systems of the heat conduction and motion equations are derived using the variational method. The order of the equations depends on the number of layers and terms in expansions of temperature and displacements of each layer. An analytical solution of the dynamic thermoelastic problem is presented for a cross-ply laminated rectangular plate with simply supported edges. The reliability of the results is confirmed by a comparison with the known exact solutions. The results based on the proposed theory can be used for verifying various two-dimensional plate theories when solving the dynamic thermoelastic problems for laminated composite plates. 相似文献
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Hamidreza Yazdani Sarvestani Mohammadreza Yazdani Sarvestani 《Applied Mathematical Modelling》2012,36(4):1570-1588
In this study, based on the reduced form of elasticity displacement field for a long laminate, an analytical method is established to exactly obtain the interlaminar stresses near the free edges of generally laminated composite plates subjects to extension, torsion, and bending. The constant parameters being in the displacement field, which describe the global deformation of a laminate, are appropriately calculated by using the improved first-order shear deformation theory. Reddy’s layerwise theory is subsequently employed for analytical and numerical examinations of the boundary layer stresses within arbitrary laminated composite plates. Various numerical results are developed for the interlaminar normal and shear stresses along the interfaces and through the thickness of laminates near the free edges. Finally the effects of end conditions of laminates and geometric parameters on the boundary-layer stress are studied. 相似文献