共查询到19条相似文献,搜索用时 203 毫秒
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复合材料加筋板剪切屈曲特性研究 总被引:2,自引:0,他引:2
《机械强度》2013,(3):288-291
分别应用半经验工程算法和有限元软件MSC.Patran/Nastran对复合材料加筋板进行剪切稳定性计算,得到结构的失稳临界载荷;开展复合材料加筋板剪切稳定性试验,得到结构的屈曲形式、失稳载荷、破坏过程及破坏载荷。实验结果表明,复合材料加筋板的破坏形式主要表现为筋条的脱胶和蒙皮的破损,该型结构具有一定的后屈曲承载能力。研究表明,工程算法、有限元计算结果与试验所得局部屈曲载荷较吻合,说明工程算法和有限元模拟方法可以用来对该型结构的稳定性能进行分析,从而为该型结构的优化设计及工程应用提供分析参考。 相似文献
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搅拌摩擦焊接加筋板轴压稳定性研究 总被引:2,自引:0,他引:2
运用半经验公式对采用搅拌摩擦焊接技术的加筋板轴向压缩局部屈曲临界应力进行工程计算,并应用有限元软件ABAQUS对该型结构的稳定性进行数值计算,得到结构的失稳屈曲临界载荷;参考工程计算和有限元计算值,对加筋板进行轴向压缩试验,对其屈曲形式、失稳及破坏载荷进行试验研究,并考虑侧边支持条件对结果的影响。试验分析表明,非承载边的约束条件对试件的屈曲载荷有一定的影响,而对试件的承载能力影响较小;搅拌摩擦焊加筋板具有一定的后屈曲承载能力;有限元计算结果与试验结果较吻合,说明模拟方法可以用来对该型结构的稳定性能进行分析,从而为该型结构的优化设计及工程应用提供分析参考。 相似文献
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加筋壁板是航空结构中常用结构形式,不同筋条形式和不同制造工艺会影响其力学行为及其失效模式.针对钛合金加筋板,采用有限元方法建立数值计算模型,研究了T型、L型和Z型3种不同截面形式筋条对加筋板的屈曲模态和破坏形式的影响机制,分析了焊接、点焊和铆接不同制造工艺对加筋板的屈曲载荷和后屈曲特性的影响.结果 表明:T型加筋板的屈... 相似文献
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通过落锤冲击试验分别在复合材料加筋壁板的蒙皮中央、长桁平筋边缘和长桁轴线处冲击出深约1mm的凹坑,然后对其进行轴压试验,研究了损伤位置对加筋壁板轴压承载能力的影响,并与未损伤试样进行了对比。结果表明:损伤位置对复合材料加筋壁板轴压承载能力有很大影响,损伤位于蒙皮中央、长桁平筋边缘、长桁轴线处加筋壁板的屈曲载荷分别为未损伤加筋壁板的83.1%,90.7%,96.1%,破坏载荷分别为未损伤加筋壁板的90.2%,84.8%,79.7%;蒙皮对加筋壁板的整体稳定性起主要作用,筋条对加筋壁板的最终承载能力起主要作用。 相似文献
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制备了CCF300碳纤维/BA9916-II环氧树脂复合材料加筋壁板,研究了该加筋壁板在干态和湿热状态下的压缩行为;建立加筋壁板有限元模型,使用经验公式对湿热环境下的材料参数进行修正,通过模拟分析了不同状态加筋壁板的压缩屈曲与后屈曲行为,并进行了试验验证。结果表明:加筋壁板在干态与吸湿状态下均有较强的后屈曲承载能力;湿热环境会对加筋壁板稳定性与承载能力造成较大负面影响,随吸湿时间延长,其屈曲及破坏载荷均呈先快后慢的下降趋势;模拟得到干态加筋壁板的屈曲载荷和破坏载荷与试验结果的相对误差分别为3.1%和5.2%,吸湿饱和态下的相对误差分别为5.6%和6.9%,误差较小,证明了所采用模拟方法的准确性和所建立有限元模型的合理性。 相似文献
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《机械制造与自动化》2017,(2):112-115
对整体加筋板试验件的结构形式和剪切试验的提前失效进行了阐述,通过有限元模拟分析其失效原因,进而对结构设计改进。基于有限元分析,试验验证结果表明,改进后的试验件发生剪切失稳后继续承载,直至破坏,失效模式正确;改进后的试验件破坏载荷是前期试验件的2.78倍,明显提高了结构的承载能力,说明剪切试验件角区细节设计至关重要。研究成果为整体加筋壁板剪切试验提供了设计思路和试验支持。 相似文献
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Most researches on the static performance of stiffened panel joined by friction stir welding(FSW) mainly focus on the compression stability rather than shear stability. To evaluate the potential of FSW as a replacement for traditional rivet fastening for stiffened panel assembly in aviation application, finite element method(FEM) is applied to compare compression and shear stability performances of FSW stiffened panels with stability performances of riveted stiffened panels. FEMs of 2024-T3 aluminum alloy FSW and riveted stiffened panels are developed and nonlinear static analysis method is applied to obtain buckling pattern, buckling load and load carrying capability of each panel model. The accuracy of each FEM of FSW stiffened panel is evaluated by stability experiment of FSW stiffened panel specimens with identical geometry and boundary condition and the accuracy of each FEM of riveted stiffened panel is evaluated by semi-empirical calculation formulas. It is found that FEMs without considering weld-induced initial imperfections notably overestimate the static strengths of FSW stiffened panels. FEM results show that, buckling patterns of both FSW and riveted compression stiffened panels represent local buckling of plate between stiffeners. The initial buckling waves of FSW stiffened panel emerge uniformly in each plate between stiffeners while those of riveted panel mainly emerge in the mid-plate. Buckling patterns of both FSW and riveted shear stiffened panels represent local buckling of plate close to the loading corner. FEM results indicate that, shear buckling of FSW stiffened panel is less sensitive to the initial imperfections than compression buckling. Load carrying capability of FSW stiffened panel is less sensitive to the initial imperfections than initial buckling. It can be concluded that buckling loads of FSW panels are a bit lower than those of riveted panels whereas carrying capabilities of FSW panels are almost equivalent to those of riveted panels with identical geometries. Finite elem 相似文献
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A. K. L. Srivastava P. K. Datta A. H. Sheikh 《International Journal of Mechanical Sciences》2003,45(1):1299-93
The buckling and vibration characteristics of stiffened plates subjected to in-plane partial and concentrated edge loadings are studied using finite element method. The initial stresses are obtained considering the pre-buckling conditions. Buckling loads and vibration frequencies are determined for different plate aspect ratios, edge conditions and different partial non-uniform edge loading cases. The non-uniform loading may also be caused due to the supports on the edges. The analysis presented determines the stresses all over the region for different kinds of loading and edge conditions. In the structural modelling, the plate and the stiffeners are treated as separate elements where the compatibility between these two types of elements is maintained. The vibration characteristics are discussed and the results are compared with those available in the literature. Buckling results show that the stiffened plate is less susceptible to buckling for position of loading near the supported edges and near the position of stiffeners as well. 相似文献
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利用有限元软件建立轴压正置正交加筋薄壁圆柱壳的参数化有限元分析模型,研究结构参数对薄壁加筋圆柱壳结构的临界载荷和屈曲模式的影响。随着蒙皮厚度的增加,结构的屈曲模式由局部屈曲逐步变化到总体屈曲,屈曲载荷上升;随着加筋厚度或宽度的增加,由总体屈曲变化到局部屈曲,屈曲载荷上升。通过等体积时的参数变化对屈曲载荷和屈曲模式的影响研究,表明在对应某体积的设计中,只有一种设计使结构屈曲载荷达到最大,而当此最大的屈曲载荷等于设计载荷时,是最轻重量的设计。在此基础上发展一种基于APDL(Ansys parametric design language)语言的薄壁加筋圆柱壳结构优化设计方法,利用该方法给出设计算例的优化结果。 相似文献
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Yuhua Tang 《International Journal of Mechanical Sciences》2011,53(2):91-97
Buckling analysis of symmetrically laminated rectangular plates with parabolic distributed in-plane compressive loadings along two opposite edges is performed using the Rayleigh-Ritz method. Classical laminated plate theory is adopted. Stress functions satisfying all stress boundary conditions are constructed based on the Chebyshev polynomials. Displacement functions for buckling analysis are constructed by Chebyshev polynomials multiplying with functions that satisfy either simply supported or clamped boundary condition along four edges. Methodology and procedures are worked out in detail. Buckling loads for symmetrically laminated plates with four combinations of boundary conditions are obtained. The proposed method is verified by comparing results to data obtained by the differential quadrature method (DQM) and the finite element method (FEM). Numerical example also shows that the double sine series displacement for simply supported symmetrically laminated plates having bending-twisting coupling may overestimate the stiffness, thus providing higher buckling loads. 相似文献
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This paper is concerned with computational problems arising in the application of a previously published matrix analysis of the stability and vibration of structures consisting entirely of a series of thin flat rectangular plates connected together along longitudinal edges. The theory requires that the conditions at the ends of the structure permit a mode which varies sinusoidally in the longitudinal direction, and it is then possible to consider each individual flat plate as one element having four degrees of freedom at each of its two longitudinal edges. The corresponding stiffness matrices are essentially exact within the spirit of thin plate theory. The main computational problem is that of testing whether or not, for a specified wavelength of buckle, any chosen value of the compressive stress is less than or greater than the lowest buckling stress of the structure. This problem is discussed in detail, and a systematic test procedure is derived. Examples of panels with integral unflanged stiffeners, bonded Z-section stiffeners, bonded top-hat stiffeners and corrugated-core sandwich panels are discussed. 相似文献
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P. R. Jeyakrishnan Kn K. S. K. Chockalingam R. Narayanasamy 《The International Journal of Advanced Manufacturing Technology》2013,65(5-8):803-815
In the present work, an avant-garde study on Buckling of honeycomb sandwich panel of hexagonal cell has been carried out by considering simply supported boundary constraints explicitly. A novel theoretical formulation has been developed for the buckling of honeycomb panel as per Mil Standard (MIL-HDBK-23A). The laminate element type has been considered for linear static analysis using Lanczos Method (finite element method (FEM)). The buckling analysis carried out by FEM has been compared and validated with theoretical and experimental investigation for different panel aspect ratio under static load. 相似文献
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David T. Huang 《International Journal of Mechanical Sciences》2010,52(10):1299-659
A point receptance array is proposed to study behaviors of panel structures with stiffeners. Although the overall objective is intended to develop a general algorithm for large structural members with stiffeners of arbitrary arrangements, the present study focus on an analytical evaluation of the accuracy of the approximation. To simplify the formulations, a thin plate with two diagonally connected beam stiffeners is selected. By solving governing differential equations for the plate and beam, point receptances that represent the interaction and compatibility conditions at the plate-beam interfaces are analytically obtained. Buckling modes of the stiffened plate are obtained by solving an eigenvalue problem. Accuracy of the approach is verified by a comparison of the analytical solution with data obtained from a direct finite element model. A parametric study was also performed. Good agreement indicates that the point receptance is a viable approach for general applications. 相似文献
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内压作用下发动机反向封头的稳定性是设计中的考虑重点.采用轴对称有限元方法对不同设计参数的等厚度和变厚度两大类反向封头进行稳定性研究,模型考虑封头开口加强环及封头与圆柱段连接处的局部加强影响.参数化研究椭球比、壁厚对封头临界屈曲载荷的影响.研究结果表明,等厚度反向封头的外形和变厚度的壁厚对结构临界屈曲载荷的影响十分敏感,在最小厚度一定的情况下,椭球比为1.413的变厚度封头是最小质量设计.另外文中给出可供工程实际设计参考的图表及曲线. 相似文献