ANALYSIS OF HOLES FORMING PROCESS BY CONICAL PUNCH IN THICK-SHEET WORKPIECES
DOI:
https://doi.org/10.20535/2305-9001.2014.70.35250Keywords:
flanging, finite element method, strengthening numerical experimentAbstract
Purpose. The aim is to perform a theoretical analysis of extrusion holes in the sheet blanks by conical punch, getting analytical relations for the determination of stresses on the contact surfaces and the deforming force.
Design/methodology/approach. Analysis was performed by co-decision approximate equilibrium equations and the plasticity condition (engineering method). Metal considered isotropic, rigid-hardening. To check the results of calculations obtained by the analytic dependence was conducted numerical experiments using the finite element method (FEM) extrusion.
Findings. With the increase in the relative thickness of the preform extrusion force decreases due to the decrease of the friction forces on the contact surfaces of the workpiece. Difference between the results with data on FEM (540 kN) was 8.5%. For designing the extrusion die tooling necessary to have data on the effort that perceives clamp in forming holes.
Dimensions deformation zone in the workpiece and the value of hardening of the deformed metal can be estimated from the distribution of the stress intensity σі.Originality/value. By joint decision of the approximate equations of equilibrium with the condition of plasticity analysis of extrusion processes conical punch holes in the slab which is used for profiling source billets for subsequent flare. Analytical dependences to determine the normal stress on the contact surfaces and the efforts of the extrusion.
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