无应力奇异性条件下的界面应力集中问题研究

ON THE STRESS CONCENTRATION ALONG INTERFACES WITHOUT STRESS SINGULARITIES

  • 摘要: 应用有限元分析技术,对无应力奇异性条件下的双材料粘接接头的应力集中问题进行了数值研究。首先,根据特征方程分析求解出消除接头界面端和界面角奇异应力场的材料组合和几何条件;据此提出了几种无应力奇异性影响并且为宏观等截面的双材料粘接接头几何模型。然后在轴对称假设条件下,对上述模型理想粘接界面上的应力分布进行了分析,着重讨论了材料组合和界面几何形状对这些应力大小的影响。结果表明:由于材料性能错配,界面上的应力集中现象不可避免,其大小依赖于材料组合和界面几何形状。这些分析结果对于指导界面几何形状优化设计,最终提高界面强度具有一定的参考价值。

     

    Abstract: The problem of stress concentrations in a bi-material bonded joint is investigated numerically using finite element analysis under the condition of without stress singularities. Firstly, the geometry and combination of materials for eliminating stress singularity near interface corners and edges in a joint are determined based on analyses of eigenvalue equations. Several geometric models of a bi-material bonded joint with constant section but without stress singularities are developed according to the solutions. Subsequently, the stress distributions along the interface of the models are analyzed under the axisymmetric assumption. The emphasis is placed on the effects of material combinations and the interface shape on the stress concentrations along the interface. The results show that the stress concentration is inevitable due to the mismatch of materials. The degree of the stress concentration depends on both material combination and the interface geometry. It is expected that this work could provide useful information for geometric optimization of the interface, with the goals of designing bi-material joints with higher interfacial strength.

     

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