Good Afternoon Community / Werner Exinger,
Attached is copy of the file that the community was helping me to resolve previously. My goal this time is to calculate alpha as shown in the worksheet. I develop a routine for alpha_v, but my results are not the same as the author whose result is reproduce as alpha_1, with the same 3 X 3 pile group. Would anybody be kind to tell me what I am doing wrong.
I already wrote in the file I sent lastly that I have no idea of the calculations you are doing. So I can't check if you are using correct formulas or the like.
I only noticed that the matrix S.p you told us is the correct one is not the one calculated by this sheet, But I suspect the matrix you provided is not correct because of the zeros not in the diagonal. They throw an error because your routines alpha0 and alpha90 can not work with x=0 (x^-0.5 gives a singularity/divison by zero). So I guess the values for S.p calculated by your sheet are the better choice anyway.
Furthermore I noticed that the special treatment of xi=0° and 90° would not be necessary, but thats just cosmetic and it won't hurt if you leave it the way you did.
So I guess I can't help other than suggesting to recheck the formulas, test them for a single pair of xi / S.p and compare with the value you think you have to achieve.
So you may consider marking this thread as assumed answered and posting the correct solution in case someone comes here later beacuse he is just searching for information about this very subject.
Good Morning Werner,
For your information, please see attached PDF file of the problem I was trying to solve. The Author shows the orientation of xi. See the example in the attached file.