正交胶合木力学性能的研究综述

Mechanical Properties of Cross Laminated Timber

通过概述正交胶合木力学性能和影响因素,阐明正交胶合木力学性能模型预测分析以及正交胶合木在高应力作用下的破坏模式;并对在抗震、抗火条件下正交胶合木力学行为特征的研究进行总结。其中正交胶合木力学性能影响因素主要从物理构造特性、制备工艺、锯材种类3个方面进行综述;由于正交胶合木属于新兴材料,对其力学性能评估过程漫长且资源消耗量大,国内外学者利用有限元模拟建立力学模型,对正交胶合木力学性能进行预测,并利用层板力学性能通过模型计算正交胶合木的力学性能,有效减少了工作内容。正交胶合木在外力作用下的破坏模式主要是横向层锯材的滚动剪切破坏、胶层破坏直至最终的底层受拉破坏,而影响正交胶合木力学性能最主要的因素就是横向层锯材的滚动剪切破坏。在火灾条件下正交胶合木的力学行性能主要取决于木材自身的特性,高温对层间剪切性能影响不大。针对CLT抗震行为的研究,主要利用计算机模拟地震条件对正交胶合木力学行为的影响。针对目前正交胶合木力学性能研究中尚未解决的问题及有待进一步开展的研究项目提出建议,利用断裂力学及微观力学对正交胶合木的破坏机制进行研究。

In this paper,the mechanical properties and influencing factors of CLT are introduced,the prediction and analysis of CLT mechanical properties model and the failure mode of CLT under high stress level are illustrated,and the mechanical properties of CLT under the condition of earthquake resistance and fire resistance are summarized.The influencing factors of mechanical properties of CLT are mainly summarized in 3 aspects:physical structure characteristics,preparation technology and types of sawn timber.In terms of mechanical calculation and simulation,as CLT is a new material,its mechanical property evaluation process is long and resource consumption is large.Scholars at home and abroad use finite element simulation to establish a mechanical model to predict the mechanical properties of CLT.The mechanical properties of CLT were calculated by using the mechanical properties of laminates,which reduced the work content effectively.The failure mode of CLT under external force is mainly the rolling shear failure of transverse layer sawn timber,the rubber layer failure and the ultimate bottom layer tensile failure,while the most important factor affecting the mechanical properties of CLT is the rolling shear failure of transverse layer sawn timber.Under fire conditions,the mechanical properties of CLT mainly depend on the characteristics of wood itself,and high temperature has little effect on interlayer shear properties.The research on seismic behavior mainly uses computer to simulate the influence of seismic conditions on CLT mechanical behavior.In view of the unsolved problems in the current research on mechanical properties of CLT and the research projects to be further carried out,it is suggested to use fracture mechanics and micromechanics to study the fracture mechanism of CLT.