Numerical Simulation Of Mechanical Properties Of Self-compacting Concrete Beams Based On Steel Fiber Orientation

As a new type of high performance composite material,steel fiber self-compacting concrete has good mechanical properties and working performance.Adding steel fiber into concrete can prevent crack propagation and increase the strength and toughness of concrete.Self-compacting concrete has good construction performance,and it can meet the needs of complex shape and dense reinforcement structure.After pouring,the orientation distribution of steel fibers will affect the mechanical properties of self-compacting concrete.As a kind of multi-phase flow and heterogeneous composite material,the numerical simulation research of self-compacting concrete based on the orientation of steel fibers is less.In this paper,a numerical simulation method for simulating the mechanical properties of self-compacting concrete beams based on steel fiber orientation is proposed by comparing with experimental data.According to the test model,the corresponding numerical calculation models are established respectively.Moldex3 d software is used to simulate the concrete pouring process and calculate the distribution probability of steel fibers along the X,Y and Z axes in each element after pouring.Then the reinforcement ratio in three directions of the unit is calculated.On this basis,the mechanical properties of steel fiber self-compacting concrete beams are calculated by Final-v11 software.The accuracy of the numerical simulation method is verified by comparing the load-displacement curve,initial crack load,ultimate load and crack location of the beam with the test.The variable parameter research continues by using the numerical simulation method.The effect of pouring position,pouring speed and steel bar diameter on the orientation of steel fibers is studied by Moldex3 d software.The effect of pouring position,pouring speed,volume fraction of steel fiber and diameter of steel bar on mechanical properties of concrete beams is studied by using Final-v11 software.The conclusions we can draw provide reference for engineering design and construction.The results show that when the pouring position moves from the end of the beam to the middle,the total volume of steel fibers distributed along the beam length decreases gradually.As the pouring speed increases,the volume of steel fibers distributed along the beam length increases.Increasing the diameter of reinforcing bars will slightly increase the volume of steel fibers distributed along the beam length.When the pouring position moves from the end of the beam to the middle,the bending resistance of the concrete beams decrease significantly.In a certain pouring speed range,increasing the pouring speed is beneficial to improve the bending resistance of concrete beams.With the increase of steel fiber volume and steel bar diameter,the bending resistance of concrete beams will be significantly improved.