木塑结构板材的可靠性预测

Reliability prediction for wood-plastic structural planks

通过纵波传播、纵向共振和弯曲振动三种方法对木塑结构板材的动态弹性模量(MOE)进行了无损检测。采用三点弯曲试验检测木塑结构板材的静态弹性模量和最大弯曲力(Fm)。运用最大弯曲力和动态弹性模量之间的回归方程,预测相同木塑结构板材的最大弯曲力,并采用一次二阶矩法评价木塑结构板材基于预测和检测的最大弯曲力的可靠性指标。结果表明:动态弹性模量和最大弯曲力间存在较强的相关性;基于预测最大弯曲力的可靠度大于基于检测最大弯曲力的可靠度,其最大差值为0.66%。

The dynamic modulus of elasticity（MOE） of wood-plastic structural planks was measured nondestructively by the longitudinal transmission,longitudinal vibration,and flexural vibration test.Three point bending test was used to measured the static MOE and maximum bending force（Fm）.The maximum bending force of same wood plastic structural planks was predicted by the regression formulas between dynamic MOE and Fm,and the First-Order Second-Moment method（FOSM） was used to analyze reliability index based on measured and predicted Fm.The results indicate that there is a significant correlation between dynamic MOE and Fm.The reliabilities of the wood-plastic structural planks based on predicted Fm are slightly greater than that based on measured Fm,in which the biggest difference is 0.66%.