Analysis of reaction forces in fixture locating points: An Analytical, numerical, and experimental study

Abstract

Reaction forces are important parameters in fixture design. They are generated by the clamping forces and machining loads at the fixture locating points. These forces are used as input values in the determination of clamping forces, fixture stiffness, and workpiece deformation. In this paper, an analytical model based on the minimum norm principle was developed to calculate these forces. Numerical simulations and experimental tests were performed on a 3D polyhedral workpiece to validate the model. The simulations were conducted using Abaqus® software and the experimental tests used a fixture and a 3D polyhedral workpiece. The theoretical, numerical, and experimental results showed good agreement for the normal component of reaction forces. The maximum errors of 3.9% and 15% were observed between the theoretical predictions compared to the numerical and experimental results, respectively. The model was also used to study the effects of two influential parameters, the coefficient of friction and clamping force, on the reaction forces. The good agreement between the theoretical, numerical, and experimental results demonstrated the efficiency of the proposed model in the rapid calculation of reaction forces for fixturing 3D polyhedral workpieces.

Experimental Evaluation of Flexible Fixture Stiffness for Steering Knuckles When Loading a Milling Machine Tool

“…Machining of parts with complex forms is often associated with inaccuracy, which corresponds to workpiece deflection under high cutting forces, which may occur because of the allowance deviation [6]. The clamping force also plays a significant role in ensuring minimal deformation of the workpiece, which can be achieved by properly positioning fixture elements [7,8].…”