圆高强钢管UHPC梁抗弯性能研究

为了研究三轴受压下UHPC的受力性能，以围压大小和钢纤维掺量为试验参数，进行20组UHPC试件常规三轴试验，分析UHPC的破坏形态、应力-应变曲线、峰值应力和应变等力学性能。结果表明：围压和钢纤维掺量均为零的试件破坏时呈劈裂破坏，其他试件则呈剪切破坏；围压和钢纤维掺量对应力-应变曲线弹性模量和弹性段曲线形状影响较小；随着围压增大，峰值应力和应变呈不断增大趋势；随着钢纤维掺量增大，峰值应力和轴向峰值应变呈先增大后不变和先增大后减小趋势，环向峰值应变则呈增大趋势。通过对UHPC八面体正应力-体积应变和剪应力-剪应变关系进行分析，基于Drucker-Prager二参数准则，建立了UHPC八面体破坏准则计算方法。`

Study on bending behavior of circular UHPC filled high strength steel tube beams

In order to study the mechanical performance of UHPC under triaxial compression, the conventional triaxial experiment was carried out to analyse the mechanical properties such as the failure modes, stress-strain curve, peak stress and strain by considering the confining pressure and steel fiber content as experimental parameters. The results show that: the specimens without confining pressure and steel fiber exhibit splitting failure, while the others exhibit shear failure. The elastic modulus and elastic segment curve shape of the stress-strain curves remain unchanged as confining pressure and steel fiber content change. With the increase of confining pressure, the peak stress and strain increase continuously. With the increase of steel fiber content, the peak stress increases firstly and then remains unchanged and the axial peak strain increases firstly and then decreases, while the hoop peak strain increases. Based on the Drucker-Prager two parameter criterion, the octahedron failure criterion calculation method of UHPC was established by analyzing its octahedron normal stress, volume strain relationship and, its octahedron shear stress and shear strain relationship.