Systematical research was implemented to explore the impacts of fiber reinforcement index V_fL_f/d_f (i.e., the product of fiber volume V_f and fiber aspect ratio L_f/d_f) on the energy dissipation characteristics including strain energy density and fracture energy, of polyethylene fiber-reinforced engineered cementitious composites (PE-ECC) with compressive strength varying from normal to high. Six V_fL_f/d_f values (i.e., 5, 7.5, 9, 10, 15, and 18) and five water/binder ratios (i.e., 0.14, 0.16, 0.18, 0.22, and 0.32) were considered in total. Strain energy density and fracture energy reflect the crack resistance capacity during the strain-hardening and softening processes of PE-ECC, respectively. The strain energy density of PE-ECC increased significantly with the increase of V_fL_f/d_f and the decrease of water/binder ratio. The fracture energy increased noticeably with the growth of V_fL_f/d_f, while it attained the maximum value at the water/binder ratio of 0.16. For ECC including both the strain-hardening and softening processes, neither the strain energy density nor fracture energy alone can reflect its crack resistance capacity and energy dissipation capacity comprehensively. Thus, in the design and simulation processes of ECC, both energy parameters need to be considered in the constitutive model.

进行了系统研究，以探讨纤维增强指数V _f L _f / d _f（即纤维体积V _f与纤维长径比L _f / d _f的乘积）对能量耗散特性（包括应变能密度和断裂）的影响。聚乙烯纤维增强工程水泥复合材料（PE-ECC）的能量，其抗压强度从正常到高不等。六个V _f L _f / d _f总共考虑了五个值（即5、7.5、9、10、15和18）和五个水/粘合剂比率（即0.14、0.16、0.18、0.22和0.32）。应变能密度和断裂能分别反映了PE-ECC的应变硬化和软化过程中的抗裂能力。PE-ECC的应变能密度随着V _f L _f / d _f的增加和水/粘合剂比的降低而显着增加。随着V _f L _f / d _f的增加，断裂能明显增加。，而在水/粘合剂比为0.16时达到最大值。对于同时包含应变硬化和软化过程的ECC，应变能密度和断裂能都不能单独全面反映其抗裂能力和能量耗散能力。因此，在ECC的设计和仿真过程中，两个能量参数都需要在本构模型中考虑。