Numerical Simulation On Fracture Splitting Of Tough And Brittle Material

Splitting process is a new technology developping along with engine connecting rod splitting production.It hasαgood manny adavantages for example:few procedures and inexpensive equipment investment, low costs, good-quality products, high assembly precision,strong loading capacity, etc. As a new technique it is in possession of wide application area. The subject investigated of this article is workpiece with similar structure and process institutional with connecting rod.The main work is studying the splitting processing technic ,individually analysising the splitting original positions of tough and brittle material, optimizly selecting the crack processing parameters,studying the influnce of back pressure to splitting crudy.The main purpos is that this technology could be applied in practice manufacturing activity sufficiently and improving the processing procedure of this type structural part. It is of far reaching importance to improve the quality of products, reduce the production costs, increase economic benefit and enhance competitiveness in international markets.In fracture analysis it is difficult to solve with compute numerically method because of the intricacy diversity of influencing factor,material nonlinearity and geometrical nonlinearity,etc.Although some datas could be measured by experiment it needs every respect fund of huge equipment,material,processing and consumption of human power and time. So finite element analogy method is the best of all methods of fracture analysis.It could get accuracy and systemic simulation results as well as save much experiment spending.This paper finish sevral aspect work adopting large finite element analysis software ABAQUS.1. Select representative tough material C70S6 and brittle material HT150. Do static analysis by finite element analysis software ABAQUS.Fix the splitting original positions of two material according to respective fracture criterias.The splittin original position of brittle material is unique, it is in front of the crack groove of the centrally symmetry. The splittin original positions of tough material is not unique because of its complex fracture criteria. They are in front of the crack groove in the 1/4 and 3/4 positions in the thickniss direction. Taking brittle material HT150 as an example, simulate crack propagation course applying cohesive element method of abaqus,specialisly learn splitting course. Fracture surface of splitting is ragged,because of the stress,displacement and strain are different at all points of the fracture path.2 Research the influence of back pressure to the normal stress, mises stress, equivalent plastic strain of the tough and brittle material through the medium of FEM. It is shown that separation force increases as backpressure becomes larger. Plastic deformation at fractured surface decreases with the increase of backpressure. Backpressure has no influnce to the splittin original position of brittle material whereas convergence tough material ' splittin original position,thereby its fracture surface is more level off..3. Analyses how crack notch geometric parameter influence sepration force of tough and brittle material through the medium of finite element numerical simulation. Curvature radius r ranges from 0.1mm to 0.4mm, open angleαfrom 0°to 90°,notch depth h from 0.4mm to 0.7mm. To brittle material take failure criteria most normal stress criteria and three-dimensional stress degree as analysis standard. Tough material failure criteria has two criteria : crack incept criteriaε≥εf, crack propagation criteriaσyy>σf so tough material take equivalent plastic strain, normal stress and three-dimensional stress degree as standard.The analysis results is crack notch three parameters have the same influnce to the sepration force of the two material. Notch depth influences separation force most and curvature radius takes second place and open angle has little effect. The choice range of the crack groove three parametric of the two materals is basicly the same. Selecting 0.1mm as curvature radius is logical,The deeper of the notch depht the easier of fracture in adequate conditions generally taking 0.6mm is logical.The flunce of open angle is small .Among the anglesα=60 is better.