The Experimental Research Of Dynamic Loading The Mongolian Scotch Rift Grain And Cross Grain

Wood has been one of the four architectural materials and has been widely used in many areas. The parts made of wood will inevitably be affected by dynamic load during use. The research of wood static characteristic has matured at present. But it is verv difficult to detect wood dynamic characteristic because of the complex inner structure of wood and some uncertain factors of external conditions. There are significant difference between dynamic mechanical properties and static mechanical properties of materials. With the development of science and technology, the research on wood dynamic properties has become a hot subject in the field of wood science.The paper introduces a method of detecting wood dynamic characteristics using hopkinson bar. It chooses mongolian scotch pine growing in the northeast as experimental specimens. It deduces wood stress formula and strain formula on the basic principles of one dimensional stress wave and collision and analyzes related dynamic characteristics curve and failure patterns in detail. And it puts forward constitutive equations of mongolian scotch pine. The research provides valuable reference for the research on wood dynamic characteristics.The mongolian scotch pine specimens has two kinds of grain including rift grain and cross grain, and each has two state of moisture content. The experiment detects dynamic compression property about specimens under different strain rate after debugging the device. Program matlab languages to process data and get stress strain curve used to analyze the relationship between stress and strain under different strain rate and the effect of dynamic mechanical performance under different moisture content, strain time curve used to analyze the relationship between strain time curve and actual material deformation under different strain rate and specimens failure patterns. The paper analyzes how to improve the collision ability of woodiness material according to wood dynamic characteristics and specimens failure patterns. The experiment gets stress strain fitting curve under different condition according to a lot of experimental data after matlab smoothing filter.The paper introduces a method of detecting wood dynamic characteristics. The research analyzes experiment data and material failure patterns and puts forward constitutive equations of this material by data fitting. The constitutive equations can be used to predict dynamic characteristics under some condition. This provides valuable reference for the research on wood dynamic characteristics.