Any three-dimensional finite element analysis of the failure of wood trusses necessarily incurs several markedly nonlinear effects, including the co-existence of orthotropic ductile and brittle failure modes depending on entangled tensile, shearing, and compressive stress states, and the mesh dependency inherent in the adoption of softening stress state laws. The complexity of the modelling process is even more severe in the presence of steel connectors. Furthermore, the experimental evidence shows that the failure modes and patterns often vary in a significant way even for the same specimen geometry and in the presence of highly engineered timber because of the persistence of defects and heterogeneities. Therefore, ad hoc computational models should be able to capture this peculiar variability of failure configurations. All these issues are properly tackled by the present nonlinear finite element procedure. The adoption of a regularized extension of the extended finite element method, indeed, allows for transitioning from the continuous interpolation of the displacement field within an orthotropic elastic-damaging material to a regularized discontinuous kinematic description based on a length-enriched extended finite element method. The present formulation is successfully validated by simulating experimental data concerning a set of failure tests on Laminated Veneer Lumber trusses with pulled steel connector.

中文翻译：

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通过正则化扩展有限元法对带有钢连接件的 LVL 木桁架进行失效分析的 3D 正交各向异性损伤模型

木桁架失效的任何三维有限元分析必然会产生一些明显的非线性效应，包括正交各向异性延性和脆性失效模式的共存，这取决于纠缠的拉伸、剪切和压缩应力状态，以及固有的网格依赖性。通过缓解压力州法律。在存在钢连接器的情况下，建模过程的复杂性甚至更加严重。此外，实验证据表明，由于缺陷和异质性的持续存在，即使对于相同的样本几何形状和高度工程化的木材，失效模式和模式也常常存在显着差异。因此，临时计算模型应该能够捕获故障配置的这种特殊变化。所有这些问题都可以通过当前的非线性有限元程序得到妥善解决。事实上，采用扩展有限元方法的正则化扩展，可以从正交各向异性弹性损伤材料内位移场的连续插值过渡到基于长度丰富的扩展有限元方法的正则化不连续运动学描述。通过模拟有关带有拉钢连接器的层压单板木材桁架的一组故障测试的实验数据，成功地验证了当前的公式。