Sensitivity Studies and Parameters Identification for Noisy 3D Moving AWJM Model

Didier Auroux,Vladimir Groza

doi:10.1155/2016/9608584

Abstract

This work focuses on the identification of optimal model parameters related to Abrasive Waterjet Milling (AWJM) process. The evenly movement as well as variations of the jet feed speed was taken into account and studied in terms of 3D time dependent AWJM model. This gives us the opportunity to predict the shape of the milled trench surfaces. The required trench profile could be obtained with high precision in lack of knowledge about the model parameters and based only on the experimental measurements. We use the adjoint approach to identify the AWJM model parameters. The complexity of inverse problem paired with significant amount of unknowns makes it reasonable to use automatic differentiation software to obtain the adjoint statement. The interest in investigating this problem is caused by needs of industrial milling applications to predict the behavior of the process. This study proposes the possibility of identifying the AWJM model parameters with sufficiently high accuracy and predicting the shapes formation relying on self-generated data or on experimental measurements for both evenly jets movement and arbitrary changes of feed speed. We provide the results acceptable in the production and estimate the suitable parameters taking into account different types of model and measurement errors.

Highlights

The abrasive waterjet (AWJ) machining is a nonconventional low-cost process [1] that was developed to give the opportunity to manufacture complex shapes with difficulty in cutting and milling materials regardless of their properties [2, 3]
The Abrasive Waterjet Milling (AWJM) process involves the high-speed waterjet produced by the water pump with a small nozzle and abrasive particles included in the jet flow
We extend the work presented in [18] about the mathematical method to identify required unknown parameters of the generic Abrasive Waterjet Milling (AWJM) model

Summary

Introduction

The abrasive waterjet (AWJ) machining is a nonconventional low-cost process [1] that was developed to give the opportunity to manufacture complex shapes with difficulty in cutting and milling materials regardless of their properties [2, 3]. We extend the work presented in [18] about the mathematical method to identify required unknown parameters of the generic Abrasive Waterjet Milling (AWJM) model. This model was previously developed and reported in [19,20,21,22] according to the industrial needs for microwaterjet footprints prediction. The inverse problem consists of the identification of AWJM model parameters from the experimental observations These results have to be further used to simulate the required surface profile.

AWJM Direct and Adjoint Model

Evenly Moving Waterjet

Sensitivity Study in Case of Uniform AWJ Movement

Noise as Model Parameter

Findings

Conclusion