SPACAR Wiki

User Tools

Site Tools

You are here: start » tfch
tfch

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision 		Previous revision
tfch [2017/09/20 21:14]
mark.naves [Dat file] 		— (current)
Line 1: Line 1:
-====== Three Flexure Cross Hinge ====== 
- 
-A three flexure cross-hinge is an elastic joint which has a single rotational degree of freedom and consists of three seperate leafsprings.  
----- 
-==== Description ==== 
- 
-This example shows a static simulation of a three flexure cross hinge rotating from -30 degrees (initial rotation of -30 degrees) to +30 degrees rotation  (additional rotation of +60 degrees). Each leafspring is simulated with 4 beam elements rigidly connected to each other (links connecting each leafspring not shown in visualization). The dat-file is provided at the bottom of this section. 
- 
-Rotational motion is pre-described by adding three stacked hinge elements with orthogonal rotation axes (equivalent to a spherical joint) and pre-describing rotational motion around the z-axis (rotation in the degree of freedom of the flexure joint) with the ''INPUTE'' argument.  
-<code> 
-HINGE 17 12 36 1 0 0 
-HINGE 18 36 37 0 1 0 
-HINGE 19 37 38 0 0 1 
-FIX 38  
-RLSE 17 1  
-RLSE 18 1  
-INPUTE 19 1   
-</code> 
-The deformation of the pre-described hinge-element is specified in the second part of the dat-file which is positioned between the ''end halt'' and ''end end'' arguments: 
-<code> 
-end 
-halt 
-.... 
-INPUTE 19 1 -0.523599  
-DELINPE 19 1 1.047198  
-ITERSTEP 25 50 0.0000005 1 3 50 
-.... 
-end 
-end 
-</code> 
-In this part, the ''INPUTE'' argument provides the initial rotational deformation (in radians) of the hinge element. The aditional input on top of the initial deformation is given by the ''DELINPE'' argument (in radians). When additional and initial deformations/displacements are used, the argument ''ITERSTEP'' is required. This argument controls (among other things) the number of load-steps used to solve the solution for the initial and additional load. For this example, 50 loadsteps are used for solving the initial and additional load. 
-<code> 
-ITERSTEP 25 50 0.0000005 1 3 50 
-</code> 
-Furthermore, a mass and inertia is added to the rotation center of the cross-hinge to effectively simulate an end-effector attached to the cross-hinge. 
-<code> 
-XM 11 1.000000  
-XM 12 0.001000 0.000000 0.000000 0.001000 0.000000 0.001000  
-</code> 
- 
-==== Visualization of stress levels ==== 
-{{ :stress.gif |}} 
- 
- 
-==== Vibration modes ==== 
-First parasitic vibration mode (translational mode) at 44 Hz: 
-{{ :vibration_1.gif |}} 
-Second parasitic vibration mode (translational mode) at 45 Hz: 
-{{ :vibration_2.gif |}} 
-Thirth parasitic vibration mode (torsional mode) at 53Hz: 
-{{ :vibration_3.gif |}} 
-Fourth parasitic vibration mode (out-of-plane bending mode)at 57Hz: 
-{{ :vibration_4.gif |}} 
-Fifth parasitic vibration mode at (torsional mode) 90Hz: 
-{{ :vibration_5.gif |}} 
-Sixth parasitic vibration mode at (internal mode at which the end-effector barely moves) 243Hz: 
-{{ :vibration_6.gif |}} 
- 
- 
- 
- 
-==== Dat-file ====  
-Note: this dat-file is created with a custom matlab script and releases in the beam-elements are programmatically choosen. Therefore, the selected released deformation modes in the leaf-springs migth be non-trival. 
-<code> 
-% INNER LEAFSPRING  
-X 1 -0.078218 0.063089 0.000000 
-X 3 -0.039109 0.031545 0.000000 
-X 5 0.000000 0.000000 0.000000 
-X 7 0.039109 -0.031545 0.000000 
-X 9 0.078218 -0.063089 0.000000 
-BEAM 1 1 2 3 4  
-RLSE 1 3 5  
-DYNE 1 1 2 4 6  
-BEAM 2 3 4 5 6  
-DYNE 2  
-BEAM 3 5 6 7 8  
-RLSE 3 1  
-DYNE 3 2 3 4 5 6  
-BEAM 4 7 8 9 10  
-RLSE 4 4 6  
-DYNE 4 1 2 3 5  
-FIX 1  
-FIX 2  
- 
-% rigid body to connect leafsprings 
-X 11 0.000000 0.000001 0.000000 
-BEAM 5 9 10 11 12  
-X 13 0.008331 -0.100144 0.000000 
-BEAM 6 13 14 11 12  
- 
- 
-% OUTER LEAFSPRING 
-X 15 0.066718 0.075146 -0.023546 
-X 17 0.033359 0.037573 -0.023546 
-X 19 0.000000 0.000000 -0.023546 
-X 21 -0.033359 -0.037573 -0.023546 
-X 23 -0.066718 -0.075146 -0.023546 
-BEAM 7 15 16 17 18  
-RLSE 7 3 5  
-DYNE 7 1 2 4 6  
-BEAM 8 17 18 19 20  
-RLSE 8 2  
-DYNE 8 1 3 4 5 6  
-BEAM 9 19 20 21 22  
-DYNE 9  
-BEAM 10 21 22 23 24  
-RLSE 10 4 6  
-DYNE 10 1 2 3 5  
-FIX 15  
-FIX 16  
- 
- 
-% rigid body to connect leafsprings  
-BEAM 11 23 24 11 12  
- 
- 
-% OUTER LEAFSPRING 
-X 25 0.066718 0.075146 0.023546 
-X 27 0.033359 0.037573 0.023546 
-X 29 0.000000 0.000000 0.023546 
-X 31 -0.033359 -0.037573 0.023546 
-X 33 -0.066718 -0.075146 0.023546 
-BEAM 12 25 26 27 28  
-RLSE 12 2 5  
-DYNE 12 1 3 4 6  
-BEAM 13 27 28 29 30  
-DYNE 13  
-BEAM 14 29 30 31 32  
-DYNE 14  
-BEAM 15 31 32 33 34  
-RLSE 15 4  
-DYNE 15 1 2 3 5 6  
-FIX 25  
-FIX 26  
- 
- 
-% rigid body to connect leafsprings 
-BEAM 16 33 34 11 12  
- 
-% Hinges to actuate joint  
-HINGE 17 12 36 1 0 0 
-HINGE 18 36 37 0 1 0 
-HINGE 19 37 38 0 0 1 
-FIX 38  
-RLSE 17 1  
-RLSE 18 1  
-INPUTE 19 1  
- 
-% END-effector visualization 
-X 39 -0.066718000000000 -0.075146000000000 0 
-RBEAM 20 9 10 39 
- 
-end  
-halt  
- 
-ESTIFF 1 6210306.302256 0.667169 0.410972 569.952912 0.000283 0.000283  
-EM 1 0.2321471642 0.0000213207 0.0000000154 0.0000213054 0  
-ESTIFF 2 6210306.302256 0.667169 0.410972 569.952912 0.000283 0.000283  
-EM 2 0.2321471642 0.0000213207 0.0000000154 0.0000213054 0  
-ESTIFF 3 6210306.302256 0.667169 0.410972 569.952912 0.000283 0.000283  
-EM 3 0.2321471642 0.0000213207 0.0000000154 0.0000213054 0  
-ESTIFF 4 6210306.302256 0.667169 0.410972 569.952912 0.000283 0.000283  
-EM 4 0.2321471642 0.0000213207 0.0000000154 0.0000213054 0  
-ESTIFF 7 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 7 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 8 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 8 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 9 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 9 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 10 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 10 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 12 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 12 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 13 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 13 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 14 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 14 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
-ESTIFF 15 2415385.254432 0.240182 0.159840 33.531976 0.000043 0.000043  
-EM 15 0.0902894012 0.0000012594 0.0000000060 0.0000012535 0  
- 
- 
-XM 11 1.000000  
-XM 12 0.001000 0.000000 0.000000 0.001000 0.000000 0.001000  
-INPUTE 19 1 -0.523599  
-DELINPE 19 1 1.047198  
-ITERSTEP 25 50 0.0000005 1 3 50 
- 
-end  
-end  
- 
- 
- 
-VISUALIZATION  
- 
-BEAMPROPS 1 2 3 4  
-CROSSDIM 0.033186 0.000891 
-DONOTDRAW 5  
-DONOTDRAW 6  
-BEAMPROPS 7 8 9 10  
-CROSSDIM 0.012907 0.000891 
-DONOTDRAW 11  
-BEAMPROPS 12 13 14 15  
-CROSSDIM 0.012907 0.000891 
-DONOTDRAW 16 
-BEAMPROPS 20 
-CROSSDIM 0.01 0.06 
-</code> 
- 
- 
  
tfch.1505934877.txt.gz · Last modified: 2017/09/20 21:14 by mark.naves

Page Tools

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki