Method for estimating a residual stress field in a workpiece during machining and machining process using said method

A process for machining a raw workpiece to produce a finished workpiece, said process comprising the following steps executed successively:

• an initial measurement step of measuring geometric parameters of the raw workpiece;
• an initial machining step of carrying out at least one initial machining operation on the raw workpiece to obtain a first intermediate workpiece;
• and
• at least one series of steps comprising at least the following steps executed successively:
• a first processing step of estimating a residual stress field in the first intermediate workpiece using a method for estimating the residual stress field in the first intermediate workpiece during machining, the method comprising the following steps executed successively:
• a measurement step of measuring geometric parameters of the first intermediate workpiece at a given moment during machining thereof at which a residual stress field in the first intermediate workpiece is to be known, in such a manner as to determine a geometric profile of the first intermediate workpiece;
• a first estimation step of estimating, from the geometric profile and an estimation model, subsequent deformations that the first intermediate workpiece is liable to undergo during further machining, said estimation model being trained beforehand by machine learning on so-called training workpieces in such a manner as to be able to use the geometric profile of the first intermediate workpiece and prerecorded data on the training workpieces to estimate said subsequent deformations of the first intermediate workpiece;
• and
• a second estimation step of estimating from the subsequent deformations estimated during the first estimation step and a simulation model, the residual stress field in the first intermediate workpiece, said simulation model being a generic physical model based on simulations defining a variability of the residual stress field in the first intermediate workpiece as a function of manufacturing parameters of the raw workpiece;
• the process further comprising the following steps executed successively:
• a second processing step of estimating, from the residual stress field in the first intermediate workpiece estimated in the first processing step, a subsequent mechanical behavior of said first intermediate workpiece during subsequent machining operations;
• a correction step of modifying the value of at least one machining parameter of said subsequent machining operations as a function of the subsequent mechanical behavior of the first intermediate workpiece estimated in the second processing step to minimize deformations of the first intermediate workpiece during said subsequent machining operations;
• and,
• a machining step of carrying out at least one machining operation on the first intermediate workpiece, said machining operation taking into account said modified value of said machining parameter(s) in such a manner as to obtain a second intermediate workpiece.