Study of Pressure Distribution in Compliant Coated Abrasive Tools for Robotic Polishing

Abstract

Robotic polishing applications involve the use of coated abrasive tools along with a compliant backing pad. The compliance helps in conforming to curved surfaces and also in blending with unpolished areas. This compliance and its effect are currently controlled only by empirical choice of various backing pad designs and materials. A better understanding of this important characteristic of these tools will lead to better process control. One of the effects of the compliance or stiffness of the backing pad under a certain applied load (robotic force control) is on the contact area and pressure distribution applied on the abrasive grains in that area. This pressure distribution in turn dictates how material is removed in the area of contact. Here, we report preliminary results of the pressure distribution exerted by an abrasive tool mounted on a robot using pressure film sensors and compare results with a simple finite element model.

Study of Pressure Distribution in Compliant Contact Wheels for Robotic Surface Finishing

“…al. [4]. In the first study, a compliant polishing pad removed material through abrasive slurry applied between the pad and the workpiece surface following a method known as chemical mechanical polishing (CMP), whereby the pressure distribution was assumed to follow Hertzian contact model [5].…”

Effect of polishing disc compliance on the pressure distribution and material removal

“…In some coated abrasive special coatings are made for cooling effects during polishing. Coated abrasives are described in terms of their grit size, shape, type of base and adhesive glue [14,13].…”

“…The hyperelastic material model was used for the flat and serrated wheel FE models, and the contact pressure distribution is shown in Figure 2.6 (a). Umer et al [27] created FEA models to investigate the compliance effect of glass fibre backing pad. Since the glass fibre 16 disc is considerably stiffer compared to other flexible tools, the disc was assigned elastic material property.…”

“…(a) (b) Figure 2.6 Finite element models for (a) serrated wheels and aluminium block (b) Glass fibre backing polishing tool pressure distribution [27] Apart from the Hertzian model, there were few more models using coefficients obtained from experimental trials to predict the contact pressure distribution. Feng et al [28] established a relation between the displacement of the polishing disk and the force.…”

“…Each pressure film assembly comprises an A-film and a C-film, which are used together for the colour to develop. The A-film has a polyester base and micro-encapsulated colour forming layer, while the C-film has a colour developing layer [27]. With the application of pressure, the microcapsules on the A-film break once it comes into contact with the C-film, as indicated in Figure 2.7.…”