# Introduction

A brief description of the example.

*CONTROL_CONTACT Hemispherical Punch LS-DYNA Manual Section: *CONTROL_CONTACT Additional Sections: *LOAD_SEGMENT *MAT_POWER_LAW_PLASTICITY *RIGIDWALL_PLANAR Example: Hemispherical Punch Filename: control_contact.hemi-draw.k Description: This problem includes three tools a punch, a pressure pad, a die and a workpiece. A workpiece is deep drawn by the hemispherical punch while the pressure pad and die prevents wrinkling. The load on the pressure pad is ramped, then the punch displaces in the y direction. Model: The workpiece measures 80 mm in radius and 1 mm in thickness. The punch radius is 50.0 mm and the die torus radius is 6.35 mm. The workpiece contains 528 Belytschko Tsay shell elements with 5 integration points through the thickness. The tools are rigid members. Only 1/4 of the system is modeled because of symmetry. Input: The number of integration points is 5 for the workpiece.(*SECTION_SHELL) This model contains two options to consider shell thickness. The first option is the contact surfaces are projected to the true surface of shell (*CONTRO L_CONTACT). The second option is membrane straining results in thickness changes (*CONTROL_CONTACT). The motion of the punch follows a sine function represented by load curve number 2 (Section 22). Reference: Honecker, A. and Mattiason, K.