第二章钢筋和混凝土的材料性能 二、钢筋的应力-应变关系 Stress- Strain relation ◆有明显屈服点的钢筋 Rebar with yield point a为比例极限 proportional limit Ea a为弹性极限 elastic limit a b为屈服上限 upper yield strength c为屈服下限,即屈服强度∫ lower yield strength cd为屈服台阶 yield pl ateau de为强化段 strain hardening stage e为极限抗拉强度f ultimate tensile strengths e 第二章 钢筋和混凝土的材料性能 二、钢筋的应力-应变关系 Stress-Strain Relation ◆ 有明显屈服点的钢筋 Rebar with yield point a’为比例极限proportional limit s =Ese a’ a为弹性极限elastic limit a de为强化段strain hardening stage b b为屈服上限upper yield strength c为屈服下限，即屈服强度 fy lower yield strength c d cd为屈服台阶yield plateau e fu e为极限抗拉强度 fu ultimate tensile strength fy f