论文标题
同几何层压弯曲结构的有效基于平衡的应力恢复
Efficient equilibrium-based stress recovery for isogeometric laminated curved structures
论文作者
论文摘要
这项工作着重于层压复合弯曲结构的有效应力恢复程序,该结构依赖于同几何分析(IGA)和平衡。通过厚度与校准的图层整合规则或均质化方法结合使用单个元素,3D固体同几何模型在位移(及其衍生物)和平面应力方面赋予了廉价且准确的近似值,而整个厚度应力组件则差异很差。采用进一步的后处理步骤,即使从粗大的位移溶液中,也可以回收准确的平面外应力状态。这是基于强烈形式的平衡方程的直接整合,涉及位移场的高阶衍生物。 IgA形状函数属性完全批准了这种连续性要求。后处理步骤是在本地应用的,该步骤授予没有其他耦合项在平衡中出现的,从而可以进行直接重建,而无需进一步迭代以解决平衡动量方程。几个数值结果表明,这种方法的良好性能,特别是对于具有明显半径与厚度比的复合堆栈和平原数量的复合堆栈。特别是,在后一种情况下,采用多个自由度直接与平原数量成正比的自由度的层技术在计算上需要更高的要求,因此所提出的方法可以被视为一种非常有吸引力的替代选择。
This work focuses on an efficient stress recovery procedure for laminated composite curved structures, which relies on Isogeometric Analysis (IGA) and equilibrium. Using a single element through the thickness in combination with a calibrated layerwise integration rule or a homogenized approach, the 3D solid isogeometric modeling grants an inexpensive and accurate approximation in terms of displacements (and their derivatives) and in-plane stresses, while through-the-thickness stress components are poorly approximated. Applying a further post-processing step, an accurate out-of-plane stress state is also recovered, even from a coarse displacement solution. This is based on a direct integration of the equilibrium equations in strong form, involving high order derivatives of the displacement field. Such a continuity requirement is fully granted by IGA shape function properties. The post-processing step is locally applied, which grants that no additional coupled terms appear in the equilibrium, allowing for a direct reconstruction without the need to further iterate to resolve the out-of-balance momentum equation. Several numerical results show the good performance of this approach particularly for composite stacks with significant radius-to-thickness ratio and number of plies. In particular, in the latter case, where a layerwise technique employing a number of degrees of freedom directly proportional to the number of plies would be much more computationally demanding, the proposed method can be regarded as a very appealing alternative choice.