玻璃纤维-砂浆管试件动态拉伸破坏特性试验研究

为了探究动载作用下GFRP（玻璃纤维）-砂浆管的动态拉伸破坏特性，采用分离式SHPB试验装置对2种空心率的水泥砂浆管和GFRP-砂浆管进行动态拉伸试验。结果表明:空心率越小、冲击气压和壁厚越大，试件峰值抗拉强度越大；GFRP-砂浆管的峰值抗拉强度随GFRP管壁厚的增大而不断增大，在空心率为0.292时，峰值抗拉强度随GFRP管壁厚增大呈对数函数递增，而在空心率0.187时，峰值抗拉强度随GFRP管壁厚增大呈指数函数递增；无GFRP管时水泥砂浆管呈对称四块破碎，GFRP-砂浆管在0.5~0.7 MPa冲击气压下仅有细小裂纹产生，在0.8 MPa冲击气压下，与入射杆接触部分产生“楔形”破坏，但总体保持为管状、破坏程度仍低于水泥砂浆管，表明GFRP管对水泥砂浆管具有较好的保护作用，可有效提高其动态抗拉强度。

Experimental study on dynamic tensile failure characteristics of glass fiber mortar tube specimens

In order to investigate the dynamic tensile failure characteristics of glass fiber reinforced plastic (GFRP)-mortar tube under the dynamic loading,the dynamic tensile tests on the cement mortar tube and GFRP-mortar tube with two kinds of hollow ratio were conducted by using the split SHPB test device.The results showed that the smaller the hollow ratio and the larger the impact pressure and wall thickness,the greater the peak tensile strength of the specimen.The peak tensile strength of GFRP-mortar tube increased continuously with the increase of the wall thickness of GFRP tube.When the hollow ratio was 0.292,the peak tensile strength decreased as a logarithmic function as the wall thickness of GFRP tube increased,while when the hollow ratio was 0.187,the peak tensile strength increased as a logarithmic function as the wall thickness of GFRP tube increased.When there was no GFRP tube,the cement mortar tube was broken into four symmetrical pieces,while under the impact pressure of 0.5 MPa-0.7 MPa,the GFRP-mortar tube had only small cracks,and under the impact pressure of 0.8 MPa,the parts in contact with the incident bar had the “wedge shaped” failure,but it remained tubular as a whole,and the failure degree was still lower than that of cement mortar tubes,which indicated that GFRP tube has good protective effect on the cement mortar tube,and can effectively improve its dynamic tensile strength.