基于泊松分布的木材顺纹方向统计损伤本构模型研究

A Statistical Damage Constitutive Model for Wood Along the Grain Direction Based on Poisson Distribution

基于概率密度函数构建材料统计损伤本构模型时,分布函数决定着本构模型精度。为解决现有研究中使用的分布函数大多适用于脆性材料、准脆性材料,并不适用于木材的难题,引入泊松分布函数,结合连续介质力学和木材顺纹方向变形破坏曲线几何条件,构建木材顺纹方向统计损伤本构模型。结果表明:基于泊松分布函数构建本构模型方法可行;与Weibull分布、正态分布和对数正态分布相比,泊松分布更适用于构建木材本构模型;对于木材本构模型中受拉段应力-应变曲线,也可采用对数正态分布来构建。

When constructing a material statistical damage constitutive model based on probability density function,the distribution function determines the accuracy of the constitutive model.The distribution functions used in existing research are primarily applicable to brittle and quasi brittle materials,but not wood.To solve this problem,a Poisson distribution function is introduced,combined with continuous medium mechanics and the geo-metric conditions of the deformation and failure curve of wood along the grain direction,to construct a statistical damage constitutive timber model along the grain direction.The findings revealed that the method of creating a constitutive model based on the Poisson distribution function proposed in this article was feasible;compared with Weibull distribution,normal distribution,and logarithmic normal distribution,Poisson distribution was more suit-able for constructing a wood constitutive model;for the stress-strain curve of the tensile section in the wood con-stitutive model,a lognormal distribution could also be used to build.