Numerical Studies On Mechanical Behaviors Of Multi-partition Composite Walls With Ultra-high Performance Concrete

The continuous advancement of urbanization and the construction of “two new and one heavy”(new infrastructure,new urbanization,and major projects such as transportation and water conservancy)are proposed,the higher requirements are put forward for structural engineering in terms of safety,applicability,durability,and sustainable development.High-performance structure has become the future development direction of structural engineering due to its many performance advantages such as safety,usability and environmental protection.Based on the above requirements,this paper proposes a new type multi-partition composite walls with ultra-high performance concrete,and uses numerical simulation methods to conduct preliminary exploratory research on it to provide relevant theoretical foundations and design methods for its future engineering applications.The main work and research results are as follows:(1)Establish a refined finite element model of the multi-partition composite walls with ultra-high performance concrete,and systematically verify the finite element model by comparing the simulation results with the test data to ensure the accuracy and reliability of the model.The follow-up study of mechanical properties lays the foundation for the model.(2)The failure process and mechanical behavior of the multi-partition composite walls with ultra-high performance concrete under the axial compression loads are studied.It reveals the influence of parameters include the strength of ultra-high performance concrete,steel plate strength,and steel plate thickness on the bearing capacity,initial stiffness,deformation of members under axial compression loads.And it is found that the combined effect does not contribute much to the bearing capacity.Based on this,a calculation method for the axial compression bearing capacity is proposed.In addition,compared with the normal strength concrete composite wall,it is found that the new composite wall can significantly improve the axial compression bearing capacity without reducing the ductility.(3)The bending failure process and mechanical behavior of multi-partition composite walls with ultra-high performance concrete under horizontal cyclic load are studied.It reveals the influence of parameters include ultra-high performance concrete strength,steel plate strength,steel plate thickness,shear span ratio,axial compression ratio on the seismic performance indicators include load-displacement curve,strength degradation,stiffness degradation,energy dissipation performance.Two methods,strain coordination method and full-section plasticity are used to calculate the flexural bearing capacity of the new composite wall.Compare the difference between the two results,and based on the results of the parameter model,it is recommended to use the full-section plastic method to reasonably predict its flexural bearing capacity.In addition,compared with the high-strength concrete composite wall,it is found that the use of ultra-high performance concrete can improve the seismic bearing capacity and ensure the excellent ductility and energy dissipation performance of the components.(4)The shear failure process and mechanical behavior of the multi-partition composite walls with ultra-high performance concrete under horizontal cyclic load are studied.It reveals the influence of parameters include the strength of ultra-high performance concrete,the strength of steel plates,and the shear span ratio on shear performance.Refer to and compare the calculation methods of shear capacity in different codes,and give the calculation method of shear capacity suitable for the new composite wall based on the parameterized results.In addition,the calculation results show that the tensile effect of ultra-high performance concrete is an important part of the shear capacity that cannot be ignored.