共查询到19条相似文献,搜索用时 483 毫秒
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双向压缩简支矩形板的后屈曲性态 总被引:2,自引:1,他引:2
本文从Karman板大挠度方程出发,以挠度为摄动参数,采用直接摄动法,研究了简支矩形板在面内双向压缩作用下的后屈曲性态.本文同时考虑了板初始几何缺陷的影响.计算结果与实验结果的比较表明二者是一致的. 相似文献
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基于薄板小挠度理论和Kelvin-Voigt 黏弹性本构方程,建立了黏弹性夹层环形薄板振动控制方程.采用分离变量法计算了内边固支、外边自由黏弹性夹层环形薄板的固有频率和振型,并与有限元计算结果进行比较. 分别讨论了夹心层比和内外半径比对固有频率及衰减系数的影响. 研究表明:系统频率随夹心层厚度增大,先增大后减小,而衰减系数一直增大;系统频率和衰减系数随内外半径比增大而增大. 相似文献
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基于近场动力学方法,综合分析了破片的速度、层合板的铺层方式、加筋板的筋条尺寸和破片相对筋条的冲击位置对结构损伤模式和破片剩余速度的影响。结果显示:高速破片冲击作用下,层合板会发生侵彻和穿透现象,层合板的损伤模式以基体损伤为主,且随着破片冲击速度的增大,板上下表面的损伤区域呈现出一种先增大后减小的趋势;高速破片冲击作用下,层合的板损伤扩展方向和纤维铺设方向有关,对于纤维铺层方向相同的层合板,其上下表面的损伤扩展方向一般与纤维方向相同;加筋板通过增加少量质量可以获得比层合板更好的抗破片冲击性能,且加筋板的筋条尺寸和破片相对筋条的冲击位置对加筋板的损伤具有明显影响。
相似文献8.
文章用三维弹性理论的非线性应变公式研究了弹性薄板的后屈曲特性,旨在探讨冯·卡门平板大挠度方程的可靠性范围。计算结果表明,当板中薄膜力较大时,用冯·卡门方程描述后屈曲问题会产生较大的误差。 相似文献
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《力学季刊》2017,(3)
研究了周边具有面内径向弹性约束功能梯度圆板在横向非均匀升温下的热过屈曲行为.基于von Karman薄板理论,推导出了横向非均匀加热功能梯度圆板在径向弹性约束作用下的位移形式的轴对称热过屈曲控制方程.假设功能梯度材料性质沿厚度方向按幂函数连续变化,采用打靶法求解得到非线性常微分方程边值问题,获得了周边简支和夹紧条件下功能梯度圆板的热过屈曲响应.定量分析了径向弹性约束对圆板的临界屈曲温度载荷以及热过屈曲变形的影响,给出了不同弹性约束刚度功能梯度圆板的热过屈曲平衡路径和平衡构形.数值结果表明,径向弹性约束对圆板的热过屈曲平衡路径的影响显著,随着约束刚度的减小,临界屈曲温度载荷增大. 相似文献
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假设曲线纤维的方向角沿板的长度方向按照线性规律变化,导出了纤维曲线铺设时的参考路径,将参考路径沿板的宽度方向平移可得一种曲线纤维增强复合材料单层板,当这种纤维曲线铺设的单层板对称铺放时即可得相应的曲线纤维增强复合材料层合板.基于弹性薄板的小挠度理论,建立了曲线纤维增强复合材料层合板自由振动问题的基本方程,采用微分求积法进行数值求解,得到了层合板的自振频率及相应的振型.与已有文献计算结果的比较,验证了本文计算结果的正确性.通过数值算例分析了微分求积法求解本问题时的收敛性,研究了纤维铺放路径和边界条件的不同对曲线纤维增强复合材料层合板频率及振型的影响,研究结果可为该种结构的设计提供一定的参考. 相似文献
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IntroductionRecently,compositestructureshavereceivedwideapplicationsinmodernindustriesincludingastronavigation ,aviation ,petroleumandchemicalindustry ,etc.However,thiskindofmaterialsgenerallyhavethepropertiesofviscoelasticitywiththeapparentcreepphenomenonandrelaxationbehaviors.Moreover,variousdamagewillemergeinthestructuresundertheactionofloading ,temperatureandenvironment.Damagemakesthemechanicalbehaviorsdeteriorategraduallybeforethefailure .Damageeffectswillsoftenthestiffnessofthestructure… 相似文献
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Buckling and postbuckling of moderately thick plates 总被引:1,自引:0,他引:1
沈惠申 《应用数学和力学(英文版)》1990,11(4):367-376
This paper gives the basic differential equations for finite deflections of elastic plates according to Reissner’s approximate stress distributions. The buckling and postbuckling problems of elastic rectangular plates, including the effect of transverse shear deformation, are solved and discussed, by using perturbation method suggested in ref. [8]. The postbuckling equilibrium paths of perfect and imperfect moderately thick rectangular plates are presented and compared with the results based on thin plate theory. 相似文献
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沈惠申 《应用数学和力学(英文版)》1989,10(4):373-384
In this paper, applying perturbation method to von Kármán-type nonlinear large deflection equations of orthotropic plates by taking deflection as perturbation parameter, thé postbuckling behavior of simply supported rectangular orthotropic plates under inplane compression is investigated. Two types of in-plane boundary conditions are now considered and the effects of initial imperfections are also studied. Numerical results are presented for various cases of orthotropic composite plates having different elastic properties. It is found that the results obtained are in good agreement with those of experiments. 相似文献
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The vibration of orthotropic rectangular plates having viscoelastic point supports symmetrically located on its diagonals
is analyzed. The plate is under the effect of a sinusoidally varying force at its center. The Lagrange equations are used
in the solution process. To apply the Lagrange equations, the trial function denoting the deflection of the plate is expressed
in polynomial form. By using the Lagrange equations, the problem is reduced to the solution of a system of algebraic equations.
The influence of the mechanical properties, the damping of the supports and the locations of point supports on the steady-state
response of the viscoelastically point-supported rectangular plates is investigated numerically for the concentrated load
at center for various values of the mechanical properties characterizing the anisotropy of the plate material and for various
values of damping and location of the supports for a certain stiffness value of the supports. The results are given for the
considered frequency range of the external force. Convergence studies are made. The validity of the obtained results is demonstrated
by comparing them with other solutions based on the Kirchhoff–Love plate theory. 相似文献
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In this paper, applving perturbation method to von Kármán nonlinear large deflection equations of plates by taking deflection
as perturbation parameter, the posibuckling behavior of simply supported rectangular plates under uniaxial compresion is investigated.
Two types of in-plane boundary conditions are now considered and the effects of initial imperfections are also studied. It
is found that the theoretical results are in good agreement with experiments.
The method suggested in this paper which has not been found in previous papers is rather simple and easy for the postbuckling
analysis of rectangular plates. 相似文献
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Based on the elasto-plastic mechanics and continuum damage theory, a yield criterion related to spherical tensor of stress is proposed to describe the mixed hardening of damaged orthotropic materials. Its dimensionless form is isomorphic with the Mises criterion for isotropic materials. Furthermore, the incremental elasto-plastic damage constitutive equations and damage evolution equations are established. Based on the classical nonlinear plate theory, the incremental nonlinear equilibrium equations of orthotropic thin plates considering damage effect are obtained, and solved with the finite difference and iteration methods. In the numerical examples, the effects of damage evolution and initial deflection on the elasto-plastic postbuckling of orthotropic plates are discussed in detail. 相似文献
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FuYiming LiPing'en ZhengYufang 《Acta Mechanica Solida Sinica》2004,17(3):230-238
I. INTRODUCTION The composite material and the composite structure are liable to generate damage during manufactureand under load, which will lead to a decrease of the material and structure’s mechanical properties.It is accepted that there exist four… 相似文献
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Based on the deformation hypothesis of Timoshenko's plates and the Boltzmann's superposition principles for linear viscoelastic materials, the nonlinear equations governing the dynamical behavior of Timoshenko's viscoelastic thick plates with damage are presented. The Galerkin method is applied to simplify the set of equations. The numerical methods in nonlinear dynamics are used to solve the simplified systems. It could be seen that there are plenty of dynamical properties for dynamical systems formed by this kind of viscoelastic thick plate with damage under a transverse harmonic load. The influences of load, geometry and material parameters on the dynamical behavior of the nonlinear system are investigated in detail. At the same time, the effect of damage on the dynamical behavior of plate is also discussed. 相似文献