Introduction

*MAT_SPRING
Belted Dummy with Springs
LS-DYNA Manual Section: *MAT_SPRING

Additional Sections:
*CONSTRAINED_EXTRA_NODES_SET
*CONSTRAINED_JOINT_SPHERICAL *CONTACT_SURFACE_TO_SURFACE
*DEFINE_SD_ORIENTATION *ELEMENT_DISCRETE
*LOAD_BODY_Z *MAT_DAMPER_VISCOUS
*PART_INERTIA

Example: Belted Dummy with Springs

Filename: mat_spring.belted-dummy.k

Description:
This is a simulation of the interaction between a dummy and seating system.
The dummy has an initial velocity, base vehicle acceleration, and decelerated
base.

Model:
The dummy consists of 15 ellipsoidal rigid bodies connected through cylindrical
joints, springs and dampers. The base of the seat belts and the seat
decelerates backwards relative to the dummy.

Input:
The dummy consists of rigid bodies 1 through 15. Materials 16 through 20
define the seat and material 21 and 22 define the seat belt. The rigid bodies
are constrained with respect to each of her with spherical joints
(*C ONSTRAINED_JOINT_SPHERICAL). Discrete springs and dampers between the
rigid body provide the relative stiffness and viscosity. The initial velocity
of all nodes is 14.8 units, while the acceleration of the seat and belt ends
follow an acceleration curve in the opposite direction.

Results:
LS-DYNA predicts that the dummy slides under the seat belts.

Reference:
Stillman, D. W.