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Adhesively Bonded Composite Joint Analysis

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Burner2k

Aerospace
Jun 13, 2015
193
Hi folks,
I am attempting to learn on performing a static linear (for time being) stress analysis of an adhesive bonded laminate joint. I decided to do a 3D analysis since I am interested in through the thickness stresses in the adhesive layer. Since this is the first time I am attempting the above, I wanted to have my bdf file checked for potential errors. The software I am using is Femap v11.2.2.

FYI, I was able to run the analysis without errors. But I wanted some feedback on definition of 3D solid laminate element in Femap/NX Nastran. Let me provide some info which may be required. The composite laminate (doubler) is 0.0741" thick and consists of 13 plies. While modeling the doubler in FE, I chose 2 solid elements through the thickness. I learnt later that Nastran just takes the total thickness of the laminate from PCOMP definition and allots all the plies to one solid element i.e. if I have 2 solid elements through the thickness, then I may require 2 different layups & 2 solid properties to get the correct layup orientation & thickness. This is what I have done. I hope I am correct here.

Anyways, I am posting some excerpts of the bdf file here and appreciate any thoughts on the same. Thanks in advance

PARAM,POST,-1
PARAM,OGEOM,NO
PARAM,AUTOSPC,YES
PARAM,K6ROT,100.
PARAM,GRDPNT,0
CORD2C 1 0 0. 0. 0. 0. 0. 1.+FEMAPC1
+FEMAPC1 1. 0. 1.
CORD2S 2 0 0. 0. 0. 0. 0. 1.+FEMAPC2
+FEMAPC2 1. 0. 1.
$ Femap with NX Nastran Coordinate System 3 : Doubler Lay Up Coord
CORD2R 3 0 0. 0. .01 0. 0. 1.01+
+ 7.8246-7 1. .01

$ Femap with NX Nastran Property 1 : Aluminum Skin 0.08in Thk
PSOLID 1 1 0
$ Femap with NX Nastran Property 2 : Potting
PSOLID 2 2 0
$ Femap with NX Nastran Property 3 : Adhesive 0.01in Thk
PSOLID 3 3 0
$ Femap with NX Nastran Property 4 : Doubler Bottom
PCOMPS 4 3 13 14100. 14100. 0. 0. +
+ 1 4 .0057 -45. YES +
+ 2 4 .0057 45. YES +
+ 3 4 .0057 -45. YES +
+ 4 4 .0057 45. YES +
+ 5 4 .0057 90. YES +
+ 6 4 .0057 0. YES +
+ 7 4 .00285 0. YES
$ Femap with NX Nastran Property 5 : Doulber Top
PCOMPS 5 3 13 14100. 14100. 0. 0. +
+ 8 4 .00285 0. YES +
+ 9 4 .0057 0. YES +
+ 10 4 .0057 90. YES +
+ 11 4 .0057 45. YES +
+ 12 4 .0057 -45. YES +
+ 13 4 .0057 45. YES +
+ 14 4 .0057 -45. YES
$ Femap with NX Nastran Material 1 : 2024-T3 Sheet Bare
MAT1 1 1.05+7 .33 .1 0. 0.
$ Femap with NX Nastran Material 2 : Potting
MAT1 22400000. .41 0. 0. 0.
$ Femap with NX Nastran Material 3 : Adhesive
MAT1 3 319000. .32 0. 0. 0.
$ Femap with NX Nastran Material 4 : Composite Tape
MAT11 4 2.83+72700000.2700000. .21 .019 .21 914000.+
+ 914000. 750000. .0723 0. 0. 0. 0.
 
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