土木专业外语Lesson_.PPTVIP

Lesson 18 Building Materials建筑材料 New words and phrases: elasticity stiffness secular temple pyramid stack slate timber conifer abundance spruce cabinetwork cellular grain silicon manganese seashell negligible synthetic resin thermosetting elastic modulus 弹性模量 ultimate tensile strength 极限抗拉强度 Words 1. elasticity 弹性，弹力 elastic adj. 弹性的 2. stiffness n. 刚度，硬度 stiff adj. 硬的, 僵直的, 拘谨的, 呆板的, 艰难的, 费劲的, 僵硬的 如：stiff frame 刚架， stiff girder 加劲梁 stiffen vt. 使硬, 使僵硬, 使生硬, 使粘稠 vi. 变粘, 变硬, 变猛烈 21. thermosetting 热凝性的，热固性的 thermo- 表示“热、热电”之义 如：thermoanalysis 热(学)分析 thermoalloy 热磁合金 Building Materials Materials for building must have certain physical properties to be structurally useful． 建筑材料必须具有某些对结构有用的物理性能。 Primarily，they must be able to carry a load, or weight, without changing shape permanently． 首先，它们必须能在不永久变形的情况下承受荷载或重量。 When a load is applied to a structure member，it will deform；that is, a wire will stretch or a beam will bend． 当荷载被施加到结构构件上时，构件将产生变形，即，钢丝将拉伸而梁将弯曲。 However，when the load is removed, the wire and the beam come back to the original positions． 然而，当荷载移除时，钢丝和梁都将恢复原来的状态。 This material property is called elasticity. 这种特性就被称为弹性。 Building Materials In the latter，the material begins to flow at a certain load(yield strength), ultimately leading to fracture．As examples，steel exhibits plastic behavior, and stone is brittle. 在后者中，材料在某个荷载（屈服强度）下开始塑性变形，最终导致断裂。例如，钢表现出塑性，石头则是脆性。 The ultimate strength of a material is measured by the stress at which failure(fracture) occurs． 材料的极限强度通过发生破坏（断裂）时的应力来测量。 A second important property of a building material is its stiffness． 建筑材料的第二个重要特性是它的刚度。 This property is defined by the elastic modulus, which is the ratio of the stress(force per unit area)，to the strain(deformation per unit length). 这种特性由弹性模量来定义，弹性模量是应力（单位面积的力）与应变（单位长度的变形）的比值。 Building Materials