Numerical Analysis Of Fracture Performance Of Steel Fiber Reinforced Concrete Based On Secondary Development Of ABAQUS

As one of the most common materials,concrete is widely used in construction,water conservancy,transportation and other fields,but its application in large buildings and some special buildings is limited due to its defects such as easy cracking,low strength and poor toughness.Fiber reinforced concrete has been widely used because of its advantages of high ductility and high toughness.Among them,steel fiber reinforced concrete is the most widely used,and steel fiber reinforced concrete is most widely used in various buildings,military and other important engineering projects in metallurgical,chemical and other industrial fields.For composites such as steel fiber reinforced concrete,most of them are studied by macroscopic test,and the mesoscopic numerical simulation method is a supplement to the macroscopic test,and has the characteristics of convenience and efficiency.Therefore,mesoscopic numerical simulation is of great significance to study the influence of the internal composition of composites on the whole.When studying the structure of steel fiber reinforced concrete,it is of great significance to study its fracture performance.Starting from the mesoscopic level and based on the random aggregate model,a three-dimensional mesoscopic model of steel fiber reinforced concrete is established in this paper.The extended finite element method is used to simulate the three-point bending test.Through the calculation and analysis of the simulated results,the effects of steel fiber volume ratio,steel fiber type and matrix concrete strength on the fracture performance of steel fiber reinforced concrete are studied.Combined with the existing test data,the reliability of the digital model is verified.The main work is as follows:(1)In this paper,steel fiber reinforced concrete is regarded as a three-phase composite material composed of cement mortar,aggregate and steel fiber.The quantity of aggregate is calculated by Fuller grading curve.Based on Monte Carlo method,combined with the judgment method of aggregate and fiber in three-dimensional,and through MATLAB software and corresponding command flow,the mesoscopic model of three-dimensional random aggregate and steel fiber model is established.(2)The above model is imported into ABAQUS software by specific methods,and the three-point bending test model is established by using its modeling function.Combined with the macroscopic test,the material properties of each part are given,and the experimental simulation is carried out by using the extended finite element method proposed above to explore and analyze the crack propagation path in the fracture process.(3)The derived load deflection curve is compared with the macroscopic test curve to verify the reliability of the model.Combined with the given calculation method,the factors affecting the fracture performance of steel fiber reinforced concrete are qualitatively analyzed from the mesoscopic point of view.The results show that the fracture toughness,fracture energy and critical crack mouth opening displacement of steel fiber reinforced concrete show a good upward trend with the increase of steel fiber volume ratio.Compared with milling steel fiber and corrugated steel fiber,the effect of arch steel fiber on the fracture performance of steel fiber reinforced concrete is particularly obvious.And the fracture performance of steel fiber reinforced concrete are improved to varying degrees with the increase of matrix concrete strength.(4)The results show that the mesoscopic model established in this paper can simulate the three-point bending test of steel fiber reinforced concrete to a certain extent,and can be simulated in related aspects according to this method.Suggestions and prospects for future research work are put forward.