COMPOSITE LAY-UP NOTATION 1

[StressMan2506]

Fellow composite-using engineers:

Thread327-334726 covered similar ground to my present query. I have a document containing lay-up notation [[(0,90)/(±45)]3]s.

I am working with structural analysis in which this lay-up has been interpreted as 0/45/90/-45/0/45/45/0/-45/90/45/0, i.e. 0/+45/90/-45 4/2/4/2. I can see the reasoning behind this interpretation. The first ply can be 0 or 90 (0 chosen), the second can be +45 or -45 (+45 chosen). In the first repeat, the choices have been reversed, and again in the second repeat. The second set of six plies mirrors the first, achieving symmetry.

The material is a 5-harness satin, so I have a feeling that there should be equal numbers of 0 & 90 and +45 & -45. Could anyone more acquainted with the notation than I am, please advise as to the correctness of the interpretation in the analysis file with which I am working?

I have not been able to contact the manufacturer.

Thanks in anticipation.

 

[Compositepro]

If you are working with a woven fabric, you cannot get a 45 between a 0 and 90. One ply of fabric will be a 0/90 or a +/-45. When working with unidirectional material, placing 45's between the zero and 90's is fairly common. I guess this reduces interlaminar shear stresses.

 

[StressMan2506]

Thanks Compositepro. I interpret your reply as being that, with woven material, the sequence 0/45/90 is never used. Have I got it right?

How would you interpret [[(0,90)/(±45)]3]s?

Thanks in anticipation.

 

[SWComposites]

(0,90) means one fabric ply, with warp in 0 direction, fill in 90 direction
(+/-45) means one fabric ply, warp in +45, fill in -45
NOT optional orientation

thus [[(0,90)/(±45)]3]s = 12 plies total = [0/45/0/45/0/45/45/0/45/0/45/0] where just the warp directions are noted for the fabric

 

[StressMan2506]

Thanks, SWComposites. The perfect answer; no ambiguity!