基于微波测试木材湿度引起内应力的方法研究

Method to Estimate the Internal Stresses Due to Moisture in Wood Using Transmission Properties of Microwaves

本文探讨了一种新的测试木材中由于湿度引起内应力的方法。基于微波传输特性,木材中的内应力可以通过木材中湿度的含量和微波衰减量对应的的电压来估测。表明了利用微波来测试应力的可能性,核心是将应力公式转换成电源电压单一变化的函数形式。运用该公式来进行测湿实验,测试的应力和观测的数据很吻合,并可以实现无损测试。得出用微波无损方式测试木材中由于湿度引起的应力是可行的结论。

The purpose of this paper is to offer a new method for detecting stress in wood due to moisture. Using transmission properties of microwaves, the stress in wood could be estimated from the moisture content of the wood and the corresponding power voltage of attenuation of the projected microwave. This suggests the possibility of utilizing microwaves in the field of stress detection. The core element of this method that the stress formulas were modified to the form of an uni-variable function of power voltage. By using this formula in the experiments, the measured data of the stress are identical to those from other experiments. Also, this stress detecting method makes it possible to apply nondestructive tests. Therefore, the conclusion drawn from this study is that the proposed method can be applicable for detecting stress in wood due to moisture.