低屈服点LYP160钢材本构关系研究

Constitutive behavior of low yield point steel LYP160

为了研究低屈服点钢材LYP160的本构行为并提出循环本构模型,进行了此种钢材的循环加载试验,研究其受力性能,包括单调受力性能、滞回性能、破坏模态及耗能能力等。利用Ramberg-Osgood模型,得到材料骨架曲线。采用Chaboche模型,确定了循环本构模型的关键参数,利用此模型预测低屈服点钢板剪力墙结构的滞回行为。结果表明:低屈服点钢材LYP160虽然初始屈服点低,但其抗震性能较好,延性约为普通钢材及高强度钢材的2.3~2.8倍;能量耗散系数在3.6左右,耗能能力明显高于普通钢材和高强度钢材,提高幅度约30%,LYP160钢材具有显著的单调及循环强化性能,具有较高的承载能力,其滞回特性包含了各向同性强化与随动强化两种特征,其中各向同性强化行为具有控制作用,这与普通钢材及高强度钢材有明显的区别。

In order to investigate the constitutive behaviors of low yield point steel LYP160 and propose the accurate cyclic constitutive model,cyclic tests on this steel were carried out. The mechanical performances were studied,including monotonic behavior,hysteretic behavior,failure mode and energy dissipation capacity. Ramberg-Osgood model was used to obtain the parameters of hysteretic skeleton curves. Chaboche model was adopted to calibrate the key parameters of cyclic constitutive model,which were used to predict the hysteretic behaviors of low yield point steel plate shear wall structures. The results show that though low yield point steel LYP160 has lower yield strength,its seismic behaviors are better,the ductility of LYP160 is 2. 3-2. 8 times of normal strength steel and high strength steel.The energy dissipation coefficients are around 3. 6,which are larger nearly 30% than normal strength steel and high strength steel. The LYP160 has obvious monotonic and cyclic hardening behaviors,indicating higher load-carrying capacity. The hysteretic behavior is composed of isotropic and kinematic characteristics, and the isotropic characteristic is in control,which is different from normal strength steel and high strength steel.