week-11 Joint creation and Demonstration

OBJECTIVE:

To create thed offerent type of joints like translational,revolute,cylindrical and spherical joints. That joints are created between the two rigid bodies in LS-dyna. The behaviour of the joint can be established using keywords.

PROCEDURE:

A mechanical joint is a section of a machine which is used to connect one or more mechanical part to another.Mechanical joints may be temporary or permanent ,most type are designed to be disassembled.Moat mechanical joints are designed to allow relative movement of these mechanical parts of the machine in one DOF and restrict movement in one or more others.

REVOLUTE JOINTS:

A revolute joint (also called pin joint or hinge joint) is a one-DOF kinematic pair used frequently in mechanism and machines. The joint constraints the motion of two bodies to the pure rotation along a common axis.

Create Two revolute joint with the help of shape mesher.

Create MAT_RIGID for both shell.

Create SECTION_SHELL for the model.

Spc_set need to be created.

The initial_velocity of 20m/s

Define_curve for prescribed motion.

The CONSTRAINED_REVOLUTE JOINT has been created.

Run the simulation.

DEFORMABLE BODY:

To create deformable body-------create nodal rigid body _MAT_ELASTIC.

DEFORMABLE BODY:

Create MAT_ELASTIC.

Create CNRB For revolute joint.

CYLINDRICAL JOINTS:

A cylindrial joint is a two-DOF kinematic pair used in mechanisms.Cylindrical joints provide single-axis sliding function as well as single-axis rotation,providing a way for two rigid bodies to translate and rotate freely.THis can be pictured by an unsecured axle mounted on a chassis, as it may freely rotate and translate.

RIGID BODIES:

Create CYLINDINCAL joint with the help of shape mesher.

Create MAT_RIGID for cylindrical joint.

Create section_shell.

Create displacemnt_node

The CONSTRAINED _CYLINDRICAL_JOINT has been created.

DEFORMABLE_BODY

Create MAT_ELASTIC

TRANSLATIONAL JOINT:

A Translational joint allows one part translate alonga a vector concering another part. The part can only translate,not rotate, in respect of each other.This joint has on translational degree of freedom,and the rotational degre of freedom is 0.

RIGID BODIES:

Create TRANSLATIONAL_JOINT with the help of shape mesher.

Create MAT_RIGID

Create Initial_VELOCITY

Create CONSTRAINED_TRANSLATIONAL_JOINT.

DEFORMABLE BODIES:

CREATE MAT_ELASTIC

For deformable_body_CNRB need to be created.

Create CNRB joint for translational joint.

SPHERICAL JOINT:

Three degree of freedom (spherical) joint multi-degree-offreedom (DOF) actuators are widely used in several industries .In an automobile,ball joints are spherical bearing that connects the control arms to the steering knuckles.Spherical joint is called a abll joint,their nodal point 1 and 2 coincide in the configuation.It allows the smooth movemnet in all direction,where shell elemnt is created using the shape of mesh option available in the element.

RIGID BODIES:

Create SPHERICAL_JOINT with the help of shape mesher.

Create MAT_RIGID.

Create SECTION_SHELL

Create CONSTRAINED_JOINT_SPHERICAL

DEFORMABLE BODY:

CREATE MAT_ELASTIC

Create CNRB for spherical joint.

Run the simulation after Joint the CNRB

COnclusion:

The cylindrial,translational,revolute,spherical joint between two rigid and deformable bodies are created using Ls-Dyna with the help of Ls-Dyna volumeR-1