考虑剪切变形的轴心受压GFRP圆管临界荷载

Critical loads of axially compressed GFRP round tubes considering shear deformations

为了考虑剪切变形对玻璃纤维增强复合材料(GFRP)构件屈曲荷载的影响,利用Engesser剪切变形理论,推导考虑剪切变形和初弯曲的临界荷载.应用于GFRP圆管时,考虑材料各向异性特征对剪切系数及强度的影响.对4根具有不同长细比的GFRP圆管试件进行轴压试验.结果表明,GFRP圆管在截面强度估算时应综合考虑轴向纤维压缩破坏和环向基体拉伸破坏.所推导的临界荷载计算式的结果和试验结果吻合良好.

The critical load of the members was formulated via Engesser’s shear deformation theory by considering the effects of shear deformation on the elastic buckling load of glass fiber reinforced polymer(GFRP)members.The shear deformation and the initial bending were considered.The anisotropic behavior of the material was considered in the computations of the shear coefficient and the compression strength in application of the equation to the GFRP round tubes.Compressive tests of four specimens of GFRP round tubes with different slenderness were conducted.The experimental results show that the compression failure in meridional fiber and the tension failure in circumferential matrix should be synthetically considered in estimating the sectional compression strength of the GFRP round tubes.The theoretical results obtained via the formulas presented herein for computing the critical load accorded well with the experimental results.