往复荷载下钢筋增强ECC梁受力性能研究

Study on hysteresis behavior of steel reinforced ECC beam under reversed cyclic loading

ECC是具有拉伸应变硬化特性和多裂缝开展机制的一种高延性纤维增强水泥基复合材料。通过试验研究考察了ECC的延性变形行为对钢筋增强ECC梁在往复荷载下受力性能的影响,并与普通钢筋混凝土梁进行了对比。结果表明,ECC的使用能够显著提高构件延性和耗能能力。基于ECC在往复荷载作用下的试验结果,编制了ECC在往复荷载作用下的简化本构模型程序,并且基于纤维模型对钢筋增强ECC梁在往复荷载作用下受力性能进行了数值模拟。模拟结果表明,所采用的ECC本构模型能够较为准确地模拟钢筋增强ECC受弯构件在往复荷载作用下的性能指标,如承载力、残余变形和耗能能力等。

Engineered cementitious composite （ECC） is a class of fiber reinforced cement-based composite material that has the properties of tensile strain hardening and multiple cracking mechanism.The effect of high ductility property of ECC on the response of steel reinforced ECC beam under reversed cyclic loading was experimentally investigated, and compared with conventional steel reinforced concrete beam.According to the test results, substitution of concrete with ECC can significantly improve ductility and energy dissipation capacity of the beam.For numerical simulations, a simplified constitutive model of ECC material was also proposed and coded based on the results of the reversed cyclic uniaxial test.The steel reinforced ECC beam under reversed cyclic loading was analyzed based on a fiber model program.The simulation results indicate that the proposed constitutive model fbr ECC material is reasonably accurate in simulating the hysteresis behaviors of steel reinforced ECC flexural members,such as load-carrying capacity,residual deformation,and energy dissipation capacity, etc.