一种考虑木材拉压不等强的非线性统一本构模型及试验验证

A Nonlinear Unified Constitutive Model Considering the Unequal Tensile and Compressive Strength of Wood and Its Experimental Verification

摘要: 木材作为一种天然的非均质材料，在荷载作用下同一纹理方向会表现出拉、压性能不对称的现象。为了更好地描述拉压性能不同的木材非线性力学行为，在一种用于描述木材受压的双参数本构模型的基础之上，通过引入Drucker-Prager塑性理论的静水压概念，建立了能够描述拉压性能不同的木材非线性统一本构模型。实验验证结果表明：模型描述的应力–应变曲线与实验结果吻合较好，运用本文中所建立的本构模型能够很好地描述木材在载荷作用下的非线性力学行为，而且考虑了木材同一纹理方向拉伸和压缩性能的差异。

Abstract: As a natural heterogeneous material, wood exhibits asymmetric tensile and compressive properties in the same texture direction under load. In order to better describe the nonlinear mechanical behavior of wood with different tensile and compressive properties, based on a two parameter constitutive model used to describe wood under compression, a nonlinear unified constitutive model of wood that can describe different tensile and compressive properties was established by introducing the concept of hydrostatic pressure from Drucker Prager plasticity theory. The experimental verification results show that the stress-strain curve described by the model is in good agreement with the experimental results. The constitutive model established in this paper can well describe the nonlinear mechanical behavior of wood under load, and consider the differences in tensile and compressive properties of wood in the same texture direction.