Abrasive Waterjet Machining Simulation By SPH Method

Abrasive waterjet machining (AWJM) is a non-conventional process. The mechanism of material removing in AWJM for ductile materials and existing erosion models are reviewed in this paper. With the difficulty of the fluid-solid interaction and extra large deformation problem using finite element method (FEM) or using the ALE method which reduced the automaticity of the program and made the computation expensive, we develop the SPH coupled FEM modeling for abrasive waterjet machining simulation is presented in order to overcome the above difficulty。Using this method, the abrasive waterjet is modeled by SPH particles and the target material is modeled by FE. The two parts interact through contact algorithm. The creativity of this model is multi-materials SPH particles, which contain abrasive and water and mix together uniformly. To build the model, the randomized algorithm is proposed for the actual mass percentage of the two materials. The material model for the abrasive is also presented firstly. Utilizing this model, abrasive waterjet with high velocity penetrating the target materials is simulated and the mechanism of erosion is depicted. The relationship between the depth of penetration and jet parameters, including water pressure and traverse speed etc. are analyzed based on the simulation. The result agrees well with the experimental data.In order to analyze the erosive mechanism in the process of particles impacting, several abrasive erosion model which were applied widely were summarized, and this paper proposed a new numerical method to be used to analyze the process of particles impacting, in which the single abrasive particle was modeled by the way of FE method, and the target material is modeled by the SPH coupled FE method with the contact force. And the two part of the abrasive and target were also interacted through contact algorithm. The simulation result compared with the results obtained from Finne, Bitter and Hashish model given in experiential equations, which showed that the predicted results were in agreement with the published results and experimentally and from analytical erosion models. Bashed the mocro-simulation model, this paper also analysis the effect of impact angle on contact time and the penetration depth. With the research the behavior of erosive wear by abrasives were understood embedded.It will be benefit to understand the abrasive waterjet cutting mechanism and optimize the operating parameters.