Manufacturing Solutions

Tool Motion

Tool Motion

 Previous topic Next topic Expand/collapse all hidden text  

Tool Motion

 Previous topic Next topic JavaScript is required for expanding text JavaScript is required for the print function  

The Tool Motion panel has two subpanels.

motion subpanel: Allows you to setup the tool motion parameters

history subpanel: Allows you to edit the solution control and output history parameters.

 

How do I…

expand-green-10Define tool motion
1.Click moving tool and select the tool that will have a prescribed motion.
2.Click max velocity and enter a maximum velocity for the tool.
3.Click total travel and enter the total distance that the tool is to move.

If the auto tool/build panel is used to generate the tool setup, the punch travel will be automatically calculated (distance between the punch and die less the blank thickness and gap), otherwise it must be entered by you.

4.Click starting time and enter 0.0 sec.

If necessary, you can also define a start time to delay the starting motion of the tool with respect to the other tools.

5.Define the direction of tool motion.
6.Setup options can be turned ON or OFF.  Each option is defined below.

Option

Description

termination

The termination time is calculated based on the motion for the selected moving tool.  The termination time is updated in the *CONTROL_TERMINATION card.

load curve

A trapezoidal or sinusoidal velocity time curve is created based on the maximum velocity, total travel, starting time, rise time and fall time.

prcrb_rigid

A prescribed velocity motion is assigned to the selected tool component.  A *BOUNDARY_PRESCRIBED_MOTION_RIGID card is created.
7.Click setup.

 
expand-green-10Update and remove tool motion

Update a tool motion:

1.Select the moving tool to be updated.
2.Update the necessary attributes.
3.Click on update.

 

Remove tool motion:

1.Select the moving tool to be removed.
2.Click remove.

 
expand-green-10Modify solution control and output history settings

History Output Settings

1.Click output number and enter the number of history data points (100 is default) to be written to each of the following ASCII output files:

Global Statistics (GLSTAT)

Material Energies (MATSUM)

Resultant Interface Forces (RCFORC)

Boundary Condition Forces and Energy (BNDOUT)

2.Click update.

 

D3plot Output Settings

1.Click d3plot number and enter the number of d3plot output states (10 is default) to be written to the d3plot file.
2.Click update.

 

Time Step

1.Click cycles/travel and enter a value between 100 and 1000 (500 is default)
2.Click update.

Mass scaling time step is calculated using the following formula:

Timestep = 1.0 / (max tool velocity * cycles per millimeter of tool travel)

In forming simulation, run time can be greatly decreased using mass scaling and/or artificially high tool velocity.  Both methods introduce artificial dynamic effects which must be minimized to reasonable levels in an engineering sense.  A single independent parameter describing artificial dynamic effect is the number of explicit time steps (cycles) taken per millimeter of tool motion.

More cycles per millimeter are required when the forming process allows large unrestrained sheet motion, such as in crash forming.  When the sheet is heavily constrained with binders and punch support, fewer cycles per millimeter are necessary.  For most simulations, values of between 100 and 1000 cycles per millimeter produce reasonable results.  If possible, or when it is otherwise necessary to repeat a simulation, use two different values and compare results to estimate sensitivity to artificial dynamic effects.

Source:        Maker, B. N., Zhu, X., Input Parameters for Metal Forming Simulation using LS-DYNA, Livermore Software Technology Corporation, Feb. 2000.

 

 

See also

Alphabetical List of Panels

LS-DYNA User’s Manual