Finite Element Simulation of Prestressed Concrete Hollow Slab Load Test
|Keywords||prestressed concrete hollow slab ANSYS finite element capacity|
Sufficient safety reserves and some resistance is required in the design loads of prestressed concrete hollow plate slab in the project. Maximum deflection, the maximum compressive stress of concrete and the width of concrete crack should meet the appropriate specifications. When exceeding the design load, prestressed concrete hollow slab requires good ductility, and its destruction began in the yielding of tension steel, and having significant plastic deformation. However, due to its lack of consideration of limit state of normal using or long-term overload of work state in design, the stiffness of some prestressed concrete hollow slab decreases, and the capacity does not meet the requirements. There the design capacity needs to be reassessed, and whether there is a good ductility of overload need to be observed.Currently load tests are commonly used to assess the design capacity of concrete components and to observe the plastic deformation of components under overload. But this is a very troublesome. And for important components of some large bridges, it is not allowed to remove to do load tests. At this point other methods are needed to assess the design capacity of the components and to observe the deformation after overloading. In this paper, practical engineering background, to an overpass of prestressed concrete hollow slab for the study, evaluate the design capacity and observe the deformation after overload through load tests. By means of finite element software, the paper establish nonlinear finite element model of prestressed concrete hollow slab, simulate the stress state of deformation, and thus make the right assessment for the hollow component.The main content of this work is as follows:1. The paper describes the constitutive relations of steel, concrete and carbon fiber cloth and other materials, and the corresponding yield criterion and failure criteria, and basic knowledge of reinforced concrete elements.2. The paper evaluates the design capacity of concrete hollow slab and observes the performance after overload through load tests, including concrete stress, concrete cracking and the maximum deflection of concrete hollow slab.3. The paper establishes non-linear model of prestressed concrete hollow slab using ANSYS finite element software, compare the conclusions with the experimental findings, and verify the correctness of the finite element model. The finite element model can reflect the real trend of the hollow board in the stress in the concrete, concrete cracking or maximum deflection of hollow plate. And it also can assess the design capacity of the hollow and simulate the performance of the hollow after overloading.4. The paper discusses the increase of the prestressed concrete hollow slab bearing capacity by Strengthened by CFRP. In a normal car loads, the carbon fiber has little effect to improve the bearing capacity of the hollow. But with the increase of loads, the deformation of the hollow become larger and the carbon fiber has a more and more obvious effect to improve the bearing capacity of the hollow.