三边固定三角形板在集中弯矩作用下的弯曲

文章应用混合变量法讨论在集中弯矩作用下三边固定三角形板的弯曲问题。求解出了三边固定三角形板的挠曲线方程,给出相应的图表,可为工程中直接应用。     

两对边固定两对边自由矩形板的精确解

基于 Kirchhoff薄板理论,提出双三角级数形式的挠度函数,求得了两对边固定两对边自由矩形板的精确解,计算结果表明这种解法收敛速度快,计算精度高,易于工程应用．     

重三角级数解一对边简支一对边自由的矩形板

用重三角级数分析一对边简支、另一对边自由的矩形薄板在均布荷载作用下的弯曲变形,并结合算例进行了说明,得出了这种方法求解思路清晰、收敛速度快、计算精度高的结论,以推广该方法。     

矩形钢筋混凝土双向板两向跨中弯矩及配筋设计研究

以矩形钢筋混凝土双向板为研究对象,采用弹性理论方法,分析了三种不同边界条件下,双向板短边方向跨中弯矩小于长边方向跨中弯矩时两向跨度比值。并对这种跨度比的取值范同进行了详细讨论,给出了这种情况双向板的配筋建议。最后,以两对边固定两对边简支的双向板为例,讨论其截面配筋设计。得出有益结论,可为工程实际参考。     

泉州众志金刚石工具公司创新出一种金刚石刀具模并获国家专利

正该实用新型专利由泉州众志金刚石工具有限公司张文忠、王政、唐晓发明(专利号201620381325、3)。这种刀具模具有一底板、一圆形模腔、四个张紧块、四个边挡板、至少一竖挡板、至少一对横挡板及压头;底板上设有环形模腔槽、至少一竖向槽和至少一对横向槽;圆形模腔组装于环形模腔槽上,至少一竖挡板及至少一对横挡板分别一一对应组装于至少一竖向槽和至少一对横向槽上;四个边挡板呈四边形包围竖挡板和     

四边支承混凝土矩形薄板的热弯曲

混凝土矩形薄板不仅广泛应用于土木工程领域,而且广泛应用于诸如水利、石油化工、铁路、公路等诸多领域,本文根据近年来已获得的四边简支、四边固定、三边固定一边简支、一边固定三边简支、两邻边固定两邻边简支和两对边固定两对边简支矩形薄板在横向变温作用下的挠度和内力解析解,利用MATLAB软件编制程序得到了这类矩形薄板在横向变温作用下的挠度和内力计算系数用表,从而为以后工程结构中四边支承混凝土矩形薄板在热环境下的设计计算提供了理论依据。     

铝合金门窗中三边支承玻璃面板的ANSYS分析方法

在铝合金门窗的玻璃面板计算中,一般情况下应遵循JGJ 113-2009<建筑玻璃应用技术规程>和JGJ 102-2003<玻璃幕墙工程技术规范>.但这两种规范中只给出了四边支撑玻璃面板的计算方法,并没有给出三边支撑玻璃面板的计算方法.本文将介绍有限元软件ANSYS计算三边支撑玻璃面板的方法.     

混合变量法在混合边界条件下矩形板弯曲问题中的应用

应用混合变量法求解了均布载荷作用下不同边界条件的矩形板弯曲问题,给出了一边固定邻边一半简支一半固定另外两边自由、一边简支邻边一半简支一半固定另外两边自由矩形板的挠曲线方程,并进行了数值运算,得到了一系列数据,通过与有限元程序计算结果的比较证明了给出的挠曲线方程及结果的正确性。给出的计算矩形板弯曲问题的方法不仅具有一定的理论价值,而且可以直接用于工程实际。     

临边洞口安全防护定型卡栓固定装置施工技术研究

临边洞口防护常采用膨胀螺栓进行固定，因其对原有结构有一定的破坏现象且其拆装困难，故此给现场洞口防护安装带来了诸多不便。现以抚州中心一期项目电梯井洞口临边防护固定技术为例，对洞口防护固定方式进行研究，形成一套施工便利的定型化免开孔的卡栓固定装置。     

弹性理论变分泛函的代入构成法与狭义泛函

以小位移弹性理论为例,从数学上给出了由场方程出发寻找相应的变分泛函的一般方法——代入构成法。应用此法得到了一对狭义泛函。通过狭义泛函证明了本构关系是各种变分泛函的欧拉方程。     

均布荷载作用下求解厚矩形板弯曲的功的互等定理法——两邻边简支另两邻边自由且角点支承

将功的互等定理法推广来求解基于Reissner理论的厚矩形板弯曲问题。首先,给出了厚矩形板弯曲的基本解;其次,给出了两邻边简支另两邻边自由且角点支承在均布荷载作用下厚矩形板弯曲的精确解析解;最后,分析了所分析的数值结果。     

Mechanical and thermal post-buckling analysis of FGM rectangular plates with various supported boundaries resting on nonlinear elastic foundations

Mechanical and thermal post-buckling analysis is presented for FGM rectangular plates resting on nonlinear elastic foundations using the concept of physical neutral surface and high-order shear deformation theory, and investigations on post-buckling behavior of FGM rectangular plates with two opposite simply supported edges and other two opposite clamped edges are also new. Approximate solutions of FGM rectangular plates are given out using multi-term Ritz method, and influences played by different supported boundaries, foundation stiffnesses, thermal environmental conditions and volume fraction index are discussed in detail. It is worth noting that the effect of nonlinear elastic foundation is small at the pre-buckling and initial post-buckling state and is significant with increasing deflection at the deep post-buckling state. Especially, comparisons of post-buckling for FGM rectangular plates resting on nonlinear elastic foundations with movable simply supported edge subjected to compression acting on the geometric middle surface and the physical neutral surface are innovative, and may be helpful to clarify typical mistakes in literature.     

Critical shear stress of flat rectangular plates with free edges

A numerical investigation is carried out by means of a finite element buckling analysis to determine the critical shear stress of flat rectangular plates with two opposite edges free. Plate sizes and the boundary conditions at the two edges loaded in shear are the parameters considered in this study. Results of the investigation show a considerable difference in the buckling strength of plates if the in-plane displacement normal to the loaded edges is restrained either at one or at both of those edges. The in-plane flexibility of the supports is, therefore, an important parameter to be accounted for in the structural design of such plates. Finally, the numerical investigation is also extended to the shear buckling strength of flat rectangular plates with only one free edge.     

Strength of biaxially loaded orthotropic plates

An approximate and simple method for rectangular orthotropic plates, loaded biaxially along two mutually perpendicular directions is presented. The theory is based on the energy method and it is free from difficult calculations such as those encountered when large deflection theory is used. Effects of initial imperfections are taken into account. The number and lengths of half-waves are assumed to be the same in the post-buckling stage as at incipient buckling. The finite buckled shape in the post-buckling stage is taken to be the same as that during incipient buckling. The Von Mises yield criterion is employed to determine the upper bound solution of the plate. Interaction curves for square plates subjected to longitudinal and transverse stresses, applicable to three different boundary conditions, four edges simply supported or four edges clamped or two opposite edges clamped with the other two edges simply supported, are presented in a non-dimensional form. Results for plates having different values of plate slenderness (b/t) and flexural rigidity ratios, D₂/D₁ are given.     

Buckling and vibration of stepped rectangular plates by element-based differential transform method

This paper is concerned with the determination of exact buckling loads and vibration frequencies of stepped rectangular thin-plates using differential transform method (DTM) which is the modified form or the disguised form of the Taylor's series method. The plates have multi-spans or multi-line hinges having two opposite edges simply supported and the other two edges being clamped, free or simply supported. To develop an analytical approach for buckling or free vibration of multi-span plates, we use the Levy solution that satisfies equilibrium and compatibility conditions at the interfaces. New and exact buckling in-plane loads and the natural frequencies are determined for many cases.     

求解弹性地基上带裂纹Reissner板的新方法

本文从考虑横向剪切效应的Reissner理论出发,导出了Winkler地基上两对边简支、另两对边自由的矩形板在自由边界上受单位集中弯矩作用时的Green函数,并以此作为基本解,应用边界积分方程的方法求得了Winkler地基上两对边简支、另两对边自由,在垂直于简支边的对称线上有穿透裂纹的Reissner板受均布载荷作用时的应力强度因子,同时对若干结构参数和材料参数对于应力强度因子的影响进行了分析。计算表明,本文的理论推导是正确的,数值结果是可靠的。     

求解集中载荷作用下厚矩形板弯曲的新方法

应用功的互等定理法(RTM)于求解厚矩形板的弯曲问题,得到了任意一点作用集中荷载矩形厚板弯曲问题的解析解,并将分析过程和结果与普通解析法进行了比较.其结果表明,这是求解厚矩形板弯曲的简单、通用的有效新方法.     

不同边界条件剪力键式空腹夹层板固有频率的计算

作为楼盖结构的剪力键式空腹夹层板在工程中有不同的边界条件,本文导出周边固定和两对边固定、两对边简支两种边界条件的剪力键式空腹夹层板横向自由振动的固有频率计算公式.将剪力键式空腹夹层板中的上、下肋及剪力键组成的刚架用相应的等效梁代替,因此计算模型为板和交叉梁系所组成的整体结构.应用能量法计算其横向振动的固有频率,先计算交叉梁系和板的最大位能及交叉梁系、板和剪力键的最大动能,然后由能量函数残数最小条件导出相应边界条件的剪力键式空腹夹层板固有频率的计算公式.如果令剪力键质量等于零,应用本文公式也可计算相应边界条件的带肋板类型的各种其它工程结构的固有频率.     

桩筏结构复合地基中筏板受力分析的理论计算模型与试验研究

由于缺乏刚性桩复合地基之上筏板受力的合理计算公式,目前中国高速铁路桩筏结构复合地基中筏板的设计计算仍采用简化算法,其计算结果的准确合理性尚不满足要求,为此拟对桩筏基础之上的筏板进行理论求解。选取桩筏结构中单桩作用的筏板区域作为求解单元,将该单元结构视为位于单桩和Winkler弹性地基共同支撑的四边滑支Reissner矩形中厚板,将Reissner矩形中厚板的基本方程导入Hamilton体系,利用辛几何中的分离变量及本征函数展开等方法,求出矩形中厚板弯曲问题的解析解,进而可求得复合地基上筏板的内力、挠度、桩顶反力和桩间土压力等设计值。最后将现场试验实测值与理论模型解析解的计算结果进行对比,结果采用文中理论模型计算得到的筏板弯矩、桩顶轴力及桩间土压应力等与现场实测结果吻合较好,表明在桩筏结构复合地基的筏板设计中,提出的理论模型是一种准确可靠的计算方法。