The Stress Subspace of Hybrid Stress Element and the Diagonalization Method for Flexibility Matrix H
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摘要: 证明了:1)杂交元假设应力模式线性无关是柔度矩阵非奇异的充分必要条件;以及2)等价假设应力模式形成相同的杂交元。在此基础上建立了假设应力模式的希尔伯特应力子空间,从而可以利用斯密特方法简单地得到等价的正交归一化应力模式,实现了柔度矩阵对角化,使得杂交元形成过程中完全避免了繁杂的矩阵求逆运算,极大地提高了杂交元分析的计算效率,数值算例表明该方法是确实有效的。Abstract: The following is proved:1)The linear independence of assumed stress modes is the necessary and sufficient condition for the nonsingular flexibility matrix.2)The equivalent assumed stress modes lead to the identical hybrid element.The Hilbert stress subspace of the assumed stress modes is established.So,it is easy to derive the equivalent orthogonal normal stress modes by Schmidt's method.Because of the resulting diagonal flexibility matrix,the identical hybrid element is free from the complex matrix inversion so that the hybrid efficiency is improved greatly.The numerical examples show that the method is effective.
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