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基于细观力学,采用虚拟裂纹扩展结合有限元法计算了短纤维增强复合材料纤维端部不同方向裂纹的应变能释放率,研究了网格尺寸对应变能释放率计算结果的影响,并分析应变能释放率随裂纹长度,纤维的长度、半径和含量的变化关系。研究表明:网格尺寸对应变能释放率的计算结果影响小;不同区域的裂纹,其应变能释放率受裂纹长度的影响不同;应变能释放率随裂纹扩展方向变化曲线呈对称特点,其中滑移型裂纹的扩展阻力较小;应变能释放率随着纤维长度、半径和含量的增大而增大。 相似文献
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纤维复合材料的损伤与破坏是缺陷萌生发展的过程。裂纹缺陷周围的应力变形场是影响裂纹扩展的重要因素。本文通过裂纹缺陷存在于纤维复合介质中的力学分析模型,由断裂力学中的J积分及有限元计算方法,探讨不同纤维组分和裂纹位于介质中不同位置时,应力场参量随之变化的规律,并进行了相关讨论分析。 相似文献
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从断裂力学的角度,对高压甲铵泵侧杆断裂进行力学计算,得出侧杆发生断裂的主要原因:侧杆承受交变载荷的情况下一旦产生裂纹后,裂纹会迅速扩展至临界裂纹并发生突然断裂.同时计算出侧杆的临界裂纹及初始裂纹存在时的侧杆运行寿命,并提出在以后的检修中避免发生侧杆断裂的对策. 相似文献
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在反应产物分离罐的接管法兰与筒体的焊接过程中产生了裂纹。本文从力学方面对产生的裂纹进行了分析,并针对产生裂纹的因素制定了返修及预防措施,有效的解决了接管法兰与筒体焊接裂纹问题。 相似文献
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In this study, a method has been proposed to obtain the failure envelope of brittle adhesives using the experimental failure loads of precracked single lap joints (SLJs). The proposed technique is based on the principles of linear elastic fracture mechanics (LEFM), on J-integral relations, and on results of a numerical analysis. Compared to the previous approaches, the introduced experimental method has some advantages such as low manufacturing costs and simpler test procedure. The proposed method can also provide a wide range of mode mix ratios without the need of an additional apparatus. The fracture envelope obtained from the proposed method was then verified by performing some fracture tests including double cantilever beam (DCB), end-notched flexure (ENF), and single leg bending (SLB) specimens. Good correlation was seen between the fracture envelopes of the proposed method and the ones obtained from the fracture mechanics experiments. 相似文献
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根据局部应力的理论分析,提出直立容器支承式支座处强度校核的新方法。本法具有力学概念明确,分析精细,用于工程简便、实用的特点。 相似文献
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Simpson数值积分在水平井井眼轨迹计算中的应用 总被引:1,自引:0,他引:1
本文把Simpson数值积分法与三次样条插值方法有机结合起来解决水平井井眼轨迹问题,避免了繁琐的递推公式推导,为水平井井眼轨迹的计算问题提供了一种行之有效的方法;并且引入计算点,通过求解计算点这个中间计算过程,应用经典公式,编制程序,方法简单可靠,易于实现及理解,为钻柱力学的有限元分析提供了必要的条件。 相似文献
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风力机叶片结构强度复合材料力学分析方法研究 总被引:1,自引:0,他引:1
截面结构强度分析校核方法是风力机叶片设计优化的关键问题。针对现有的叶片工程力学计算方法精度不高、有限元分析方法计算开销较大的问题,在研究风力机复合材料叶片结构设计模型的基础上,基于复合材料力学理论,推导出计算叶片截面周向各处拉伸和剪切应变的计算公式;在叶片生命周期内的极限载荷下,对某1.5 MW叶片进行了结构强度计算和分析,通过与该叶片在当量极限载荷下的测试结果对比,验证了所述方法的有效性。 相似文献
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介绍了扁平绕带式压力容器的结构特点,给出了静态力学和动态力学行为研究现状,以及结构失效分析、可靠性设计方法的研究进展。 相似文献
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The Effects of Plasticity in Adhesive Fracture 总被引:2,自引:0,他引:2
From the viewpoint of continuum mechanics, and particularly the energy concept of fracture, adhesive and cohesive failures are similar. The essential difference involves the interpretation of the energy required to create new (adhesive or cohesive) surface area. This fracture mechanics approach has in the past been applied to a number of different elastic problems. In this investigation an elastic-perfectly plastic analysis for adhesive failure of a beam is presented. This analysis accounts for the energy dissipated during plastic bending. Experimental results with 6061-T6 alumimum are presented as evidence of the validity of the approach. 相似文献
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From the viewpoint of continuum mechanics, and particularly the energy concept of fracture, adhesive and cohesive failures are similar. The essential difference involves the interpretation of the energy required to create new (adhesive or cohesive) surface area. This fracture mechanics approach has in the past been applied to a number of different elastic problems. In this investigation an elastic-perfectly plastic analysis for adhesive failure of a beam is presented. This analysis accounts for the energy dissipated during plastic bending. Experimental results with 6061-T6 alumimum are presented as evidence of the validity of the approach. 相似文献