Overview

 

What are target applications for MTT3D?

The user can easily carry out a media path simulation for the 3D movement of sheet through a machine such as printer, copier, fax, and other sheet-feeding machines

MTT3D provides the basic modeling of the sheet as paper, film, other plat sheets, Idealized rollers, and guides

 

It will also:

     Automate a generation of the contact elements between the sheets and the rollers and guides along the path they will follow.

     Give the user who is designing and analyzing the media transport system, the particular and epochal solution of modeling the discrete and flexible sheets or the continuous strips that undergo large deformations with linear material properties.

     Provide a good solution when the user checks the potential for:

    Jamming given different sheet size, weight and stiffness

    Different sheet properties due to temperature and humidity extremes

    Different sheet velocity due to misalignment of drive-driven roller sets

    Differences of roller velocities due to gap, wear or etc.

 

Group for MTT3D

To make it possible to an easy and convenience GUI, a concept of Group is introduced. Group has predefined sub-entities as bodies, joints, forces, and contacts.

For MTT3D, there are four group entities such as sheet, fixed roller and movable roller, and they make it possible to create and modify all sub-entities dependent on each group through only one time operation. Each group is made of several sub-entities as the following table.

Group

Sub Entities

Sheet

Bodies, Forces, Contact geometry

Guides

Contact to Sheet, Contact geometry

Fixed Roller

Body, Joint, Contact to Sheet, Contact geometry

Movable Roller

Bodies, Joints, Contact to Roller and Sheet, Nip Force, Contact geometry

 

Customized Contact

To handle a contact problem among a sheet and other rollers or guides in MTT3D, RecurDyn has developed a new contact element. The sheet is meshed many nodal masses. To check a contact condition between the sheet and roller:

     The sheet is discretized by triangular patches made of three nodal masses

     The roller is parameterized as a cylinder with a radius and a length.

 

Also, the cylinder to patch contact is used in checking a contact condition between the sheet and a circular guide. And the sheet is discretized by many spheres at the nodal positions in checking the contact condition between a sheet and a linear guide or an arc guide. They use a global detecting method for checking a body pair in the contact condition. The method has an advantage that the number of contact searching can be smaller than other methods for the system in which the position of most of rollers and guides are fixed on a point of the base body such as the ground or one carrier body. Most of sheet feeding machines such as a printer, copier or fax are in that case. A cylinder to cylinder contact is introduced for the roller to roller contact and a soft nip. Also, a maximum gap of a movable roller is defined as cylinder to plane contact. And all new contact elements are formulated in the 3D. The below table summarizes the new contact elements that are developed for MTT3D.

 

Group

Contacts

Fixed Roller

Roller to Sheet Contact

Movable Roller

Roller to Sheet Contact

Roller to Roller Contact

Roller to Roller Contact for Soft Nip

Roller to Plane Contact for Maximum Gap

Guides

Sheet to Arc Guide Contact

Sheet to Linear Guide Contact

Roller to Sheet Contact for a circular guide

Contact

Sheet to Surface Contact

 

Defining units

For MTT3D, it is very important to choose the unit system. In general, the sheet such as paper or film has a small mass. As the user divides the sheet into more segments, so each mass of segment bodies is smaller. So the mass may be smaller than numerical error(about 1.0e-8) in the unit system. The user should check this point in the choosing unit system. RecurDyn recommends the user to use the following unit system.

 

Step to create media transport system

1.  Build a feeding system

1.  Create a sheet

2.  Modify the contact parameter

3.  Check the assembly information

4.  Run the simulation