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在已经掌握力学课程的基础上,只要按进程学习,及时独立完成思考题和习题。这样学习《木结构》并不会发生很大的困难。《木结构》课程也有一些难点及容易混淆的地方。在学习过程中应特别注意要掌握其基本概念和要领。现例举几个问题作一简单分析,对更好地学习《木结构》有所启发、帮助。一、木材的力学性能与选材等级Ⅰ.木材是各向异性材料木材不同于其它结构的材料,木材特点之一是它的各向异性的特征。所谓各向异性,即在同一类型荷载作用下(如:受压、受拉等),由于作用在构件的不同方向,则木材的极限承载能力是不相同的。如图1所示,一立方体木材试件,在轴心压力作用下,其破坏时N_a≠N_x。这种性能就叫各向异性。为什么木材会产生各向异性现象?这就要从木材的构
On the basis of mastering the mechanics course, as long as the process is studied, the questions and exercises can be completed independently in time. Learning the “Wood Structure” in this way will not cause great difficulties. The “Wood Structure” course also has some difficulties and confusing areas. In the learning process, special attention should be paid to mastering its basic concepts and essentials. For example, we will give a brief analysis of a few issues and have inspired and helped to better study Wood Structure. First, the mechanical properties of wood and material grade I. Wood is anisotropic material Wood is different from other structural materials, one of the characteristics of wood is its anisotropic characteristics. The so-called anisotropy, that is under the same type of load (such as: pressure, tension, etc.), due to the role of different directions in the member, the ultimate load carrying capacity of the wood is not the same. As shown in Fig. 1, a cubic wood specimen under the action of the axial pressure breaks N_a≠N_x. This property is called anisotropic. Why does wood produce anisotropy?