GlossaryKind of term: Manufacturing termProcess simulation
What is process simulation?
Process simulation predicts what physically happens to material and workpiece during manufacture, such as cutting forces, heat, vibration and distortion.
Process simulation computes the physics of a manufacturing process in advance: what material, workpiece and tool do under force, heat and time. In machining that means cutting forces, temperature, deflection of tools and thin walls, vibration and distortion from residual stress. In additive manufacturing it covers shrinkage, residual stress and warping during the build, in welding the distortion after cooling. In sheet forming such as deep drawing the concerns include springback and thinning; in casting and injection moulding, filling, solidification and shrinkage. The output is a prediction from a model, not a measurement.
What does process simulation depend on?
Different methods are used. Cutting forces are often calculated with empirical or mechanistic models, distortion and temperature usually with the finite element method, and chatter behaviour with stability analyses based on the measured dynamics of machine and tool. The output depends on material data, boundary conditions such as fixturing and coolant, the condition of the stock and the resolution of the model. Residual stress in plate or bar varies by batch and is rarely known precisely, which makes predicted distortion uncertain.
How does process simulation work in practice?
A simulation that shows in advance that a thin wall is likely to chatter or a part is likely to distort once unclamped can save trial parts and scrap. Against that stand computing time, specialist software and someone to set up the model and judge the result. For a simple one-off a test cut is often quicker; with series, expensive alloys and thin-walled parts the balance shifts. Measuring the real part remains necessary.
What is process simulation often confused with?
Process simulation is not CAM simulation: CAM simulation checks the NC program for collisions, axis limits and leftover stock, process simulation works out what the material does under force and heat. And a digital twin runs alongside a real machine or product and is updated with measured data; a process simulation is a calculation made beforehand.
Frequently asked questions
When is process simulation worth it in machining?
Mainly for thin-walled parts that may chatter or distort, for expensive alloys where a trial part costs a lot, and for series in which a mistake multiplies. On a simple one-off, a test cut usually gets you there sooner.
Can you predict distortion after milling?
With a model of the residual stress in the material and the machining sequence, a simulation can give the direction and the order of magnitude. Actual distortion also depends on the batch of material and the fixturing; measuring the first part is still needed.
What does process simulation do in 3D printing?
It calculates how the part shrinks and warps during the build, so you can choose orientation, supports or a pre-compensated shape before the printer starts. How well that holds depends on the material model and process settings.
Do I need process simulation to quote a part?
Rarely. A quote turns on the route: setups, operations, time and rate. If a series or a difficult part does need simulation, it goes into the estimate as an item of its own.