SIMULATION OF INTERIM FORGING OF DEPOSITED PRODUCTS IN ANSYS MECHANICAL APDL (IMPLICIT ANALYSIS)

Abstract

The paper considers the problem of simulating the interim forging during additive manufac-turing. Wire-arc additive technologies are associated with formation of technological residual stress fields, porosity, inhomogeneous structure and anisotropy, as well as unwanted defects, such as cracks, delamination or warping of the part. Interlayer hardening via forging both com-pensates such disadvantages and improves the mechanical properties of structures. Mathemat-ical modeling is one of main methods of studying these processes. There are a lot of publica-tions on modeling the formation of fields of residual stresses and heat shrinkage deformations in products obtained using additive technologies, including the method of wire welding. The work aims at checking the adequacy of using ANSYS Mechanical APDL for numerical modeling of interim metal forming processes. In this work, the Johnson – Cook viscoplastic model from Ex-plicit Dynamics was adapted to the capabilities of ANSYS Mechanical APDL for three materials: Amg6, 12X18H10T, VT6. As a physical model in ANSYS Mechanical APDL, a multilinear iso-tropic MISO plasticity model is chosen, which, unlike the Johnson – Cook model, does not take into account the effect of strain rate on the elastic-plastic behavior of the material. The values of the material constants for the MISO model are identified. The adequacy of replacing the non-stationary statement with a quasi-static one is proved, due to a slight loss of accuracy. A three-dimensional model of bar forging for three types of materials was built and implemented, its identification and verification were carried out by comparing with the results of a full-scale exper-iment. A good agreement between the calculated data and experiment is shown. Based on the data obtained, a conclusion was made about the admissibility of using the implicit solver ANSYS Mechanical APDL for calculating the processes of interim forging of the deposited products with acceptable accuracy.