Method of Identification of Dry and Viscous Friction Forces and Construction of Dynamic Deformation Diagrams of Metals in Experiments with Impact Compression

Abstract

The influence of dry and viscous friction forces on the dynamic deformation of elastovis-coplastic tablet specimens was numerically and experimentally investigated. The main dependencies of their form-changing for metals and alloys have been established. A criterion of the shape changing of tablet specimens is proposed. A new method for identifying of the coefficients of dry friction at contact surfaces, depending on shape changing of the tablet specimens, based on numerical modeling of an axisymmetric dynamic problem and a rapidly convergent fixed-point iteration method was developed. The division of the two-parameter identification problem into two problems of one-parameter parameterization is theoretically justified with a high degree of reliability: the problem of determining of the friction coefficient and the problem of construction of the true diagram of dynamic deformation in this experiment with the friction coefficient found earlier. As a result, the dynamic deformation diagrams with frictional forces and radial inertia consideration are constructed using the iterative method. In known approximation methods of construction of the deformation diagrams with frictional forces and radial inertia consideration, friction coefficients are assumed to be known, whereas methods for their determination in experiments with impact compression are practically unavailable.