聚乙烯醇和超高分子量聚乙烯纤维对全珊瑚混凝土动态力学性能影响与数值模拟

Influence of polyvinyl alcohol and ultrahigh molecular weight polyethylene fibers on dynamic mechanical properties of coral aggregate concrete and numerical simulation

随着海洋资源的不断开发利用,在岛礁上就地取材制备全珊瑚混凝土已经成为岛礁工程建设与防护的关键技术。为探究不同有机非金属纤维掺量对全珊瑚混凝土的力学性能的影响,使用分离式霍普金森压杆(SHPB)试验研究其动态力学性能并采用LS-DYNA软件对冲击过程进行数值模拟。结果表明:当有机纤维质量分数为1.2wt%时,全珊瑚混凝土的静态抗压强度可达到113 MPa,相比未掺纤维的珊瑚混凝土增长了约7.5%。动态试验下,在应变率为120 s^(−1)时动态抗压强度可达到247 MPa,比未掺加纤维的试样提高约32.6%。全珊瑚混凝土的韧性指标也随着有机纤维掺量的增加而增大。此外,随着有机纤维掺量的增加,珊瑚混凝土试件在相同冲击条件下完整性越高。动态强度试验值与模拟值的误差7%在允许误差内。

With the continuous exploitation of marine resources,the preparation of in-situ all-coral concrete on islands and reefs has become a key technology for the construction and protection of island projects.In order to investigate the effect of different organic non-metallic fiber admixture on the mechanical properties of all-coral concrete,the dynamic mechanical properties were investigated by using the Split Hopkinson Pressure bar(SHPB)test and the impact process was numerically simulated by LS-DYNA.The results show that the static compressive strength of all-coral concrete can reach 113 MPa when the organic fiber mass percent is 1.2wt%,which is an increase of about 7.5%compared with the coral concrete without fiber dosing.Under the dynamic test,the dynamic compressive strength can reach 247 MPa at a strain rate of 120 s^(−1),which is about 32.6%higher than that of the specimens without fiber admixture.The toughness index of all-coral concrete also increases with the increase of organic fiber admixture.In addition,the integrity of coral concrete specimens increases under the same impact conditions with the increase of organic fiber admixture.The error between dynamic strength test values and simulated values is 7%to be within the allowable error.