aerostress82
Structural
Hi everyone, (Happy New Year!!)
I have performed Static Stress Analysis, Freebody Load extractions and finally Hand Calculation analysis on "wing-ribs with integrally stiffened panels" on a commercial transport category aircraft (FAR Part 25) previously. (STATIC STRESS HAND CALCULATION ANALYSIS)
What I've seen in most calculations is that there were so many additional "rotational restraint, diagonal tension redistribution, edge member flexibility, stiffener stiffness factor for pure shear and pure compression, panel edge fixity, buckling enhancement factor, panel post-buckling load redistribution, edge member flexibility effect on permanent panel buckling, stiffener flexural/local instability & similar coefficients" used to perform those analysis for the most light-weight design.
My question is, do you know of any references/approaches that guidelines "ALL analyses to be performed for panels and stiffeners" on an integrally stiffened panel design (like wing-ribs) at an intermediate level without using all these additional coefficients compiled by aircraft companies?
I'm aware of most common references used for aircraft industry like Bruhn, Niu, Roark, MIL Handbook as well as Boeing, Airbus, Bombardier, MTS004/Aerospatiale manuals. But couldn't find a solution from beginning to end for only this integrally stiffened panel type of structure. Yes, the formulas to be used are mostly in main textbooks already. But without going into any "commercial manual coefficient or graph data" constants, is there a whole guideline of how to analyze these structures at ALL aspects?
What I'm trying to do is to be able to understand the conservative / unconservative approaches already used in some Mathcad/Excel VBA combined stress hand calculation analysis in the future. It looks like a lot of companies are using these readily compiled packages (some call them black boxes - I don't) and my concern is merely safety as I am and will be in the commercial aerospace industry in the next 20-30 years ahead.
Just for the note, I'm very enthusiastic about aerospace stress analysis and have checked all above documents I mentioned before on the job as this is my hobby rather than a job.
I'm just looking to see if you-senior stress guys- have any approaches or guidelines to make sure if anything is conservative/unconservative in such a structure..
Spaceship!!
Aerospace Engineer, M.Sc. / Aircraft Stress Engineer with 7 years of experience
(United States)
I have performed Static Stress Analysis, Freebody Load extractions and finally Hand Calculation analysis on "wing-ribs with integrally stiffened panels" on a commercial transport category aircraft (FAR Part 25) previously. (STATIC STRESS HAND CALCULATION ANALYSIS)
What I've seen in most calculations is that there were so many additional "rotational restraint, diagonal tension redistribution, edge member flexibility, stiffener stiffness factor for pure shear and pure compression, panel edge fixity, buckling enhancement factor, panel post-buckling load redistribution, edge member flexibility effect on permanent panel buckling, stiffener flexural/local instability & similar coefficients" used to perform those analysis for the most light-weight design.
My question is, do you know of any references/approaches that guidelines "ALL analyses to be performed for panels and stiffeners" on an integrally stiffened panel design (like wing-ribs) at an intermediate level without using all these additional coefficients compiled by aircraft companies?
I'm aware of most common references used for aircraft industry like Bruhn, Niu, Roark, MIL Handbook as well as Boeing, Airbus, Bombardier, MTS004/Aerospatiale manuals. But couldn't find a solution from beginning to end for only this integrally stiffened panel type of structure. Yes, the formulas to be used are mostly in main textbooks already. But without going into any "commercial manual coefficient or graph data" constants, is there a whole guideline of how to analyze these structures at ALL aspects?
What I'm trying to do is to be able to understand the conservative / unconservative approaches already used in some Mathcad/Excel VBA combined stress hand calculation analysis in the future. It looks like a lot of companies are using these readily compiled packages (some call them black boxes - I don't) and my concern is merely safety as I am and will be in the commercial aerospace industry in the next 20-30 years ahead.
Just for the note, I'm very enthusiastic about aerospace stress analysis and have checked all above documents I mentioned before on the job as this is my hobby rather than a job.
I'm just looking to see if you-senior stress guys- have any approaches or guidelines to make sure if anything is conservative/unconservative in such a structure..
Spaceship!!
Aerospace Engineer, M.Sc. / Aircraft Stress Engineer with 7 years of experience
(United States)
