玻璃纤维增强聚合物腰梁受力性能试验与有限元模拟

为探究基坑支护工程中玻璃纤维增强聚合物(glass fiber reinforced polymer, GFRP)腰梁的应力分布规律和变形特性，结合GFRP腰梁力学性能试验及数值模拟，依托于青岛某深基坑工程，利用ABAQUS有限元软件对不同工况下双腹板GFRP腰梁进行了有限元模拟。研究结果表明，与钢材相比，GFRP材料具备较高的抗弯强度，但弹性模量较低；最大加载至700 kN时，双腹板GFRP腰梁变形的室内试验结果和数值模拟结果的变化规律相似，随着荷载水平的增加，呈线性变化，说明GFRP腰梁始终处于弹性工作状态，整体稳定性强。明确了预应力锚杆轴力为300 kN时GFRP腰梁在两端自由、两端约束以及一端约束一端自由3种情况下的应力分布规律和变形特征；对于两端自由的GFRP腰梁，预应力锚杆轴力为150 kN时的应力、位移约为预应力锚杆轴力为300 kN时的50%。研究结果可为类似工程提供借鉴与参考。

Experimental study and finite element simulation on mechanical properties of glass fiber reinforced polymer waist beams

To investigate the stress distribution regulation and deformation characteristics of glass fiber reinforced polymer (GFRP) lumbar beam in foundation pit support engineering. The finite element simulation of double web GFRP lumbar beam under different conditions was carried out by ABAQUS finite element software based on a deep foundation pit project in Qingdao, combining the mechanical performance test and numerical simulation of GFRP lumbar beam. The results show that the GFRP material has higher bending strength, but lower elastic modulus compared with steel. The experimental test results and numerical simulations of the deformation of the double-web GFRP lumbar beam at a maximum loading of 700 kN showed similar patterns of variation. With the increase of the load level, the linear variation was observed, indicating that the GFRP waist beam was always in elastic operating condition and the overall stability was strong. The stress distribution pattern and deformation characteristics of GFRP waist beam with 300 kN prestressing anchor axial force are clarified in three cases: free at both ends, restrained at both ends and restrained at one end and free at one end. For the GFRP waist beam with both ends free, the stresses and displacements at 150 kN prestressing anchor axial force are about 50% of those at 300 kN prestressing anchor axial force. The results of the study can be used as reference for similar projects.