Theoretical Elastic Mismatch Stresses
Abstract
Stress- magnification factors were obtained for the effect of mismatch of the middle surfaces at junctions in shell structures. The results are directly applicable only when the thickness and the slope on one side of a mismatched joint are the same as those on the other. Results are found for biaxial stress states with any principal stress ratio at the joint, including cases in which the stresses are of opposite sign. Both principal and effective stress- magnification factors are given for long or local mismatch. The results are presented both graphically and in equation form. As expected, the increase in stress is substantially higher when the membrane stress normal to the mismatch is greater in magnitude than that parallel to the mismatch. The effective stress factors are highest when the membrane stress normal to the mismatch is about twice the membrane stress parallel to the mismatch. This case would occur, for example, at a longitudinal seam in a cylindrical pressure vessel. Principal stress- magnification factors for a given amount of mismatch do not vary with stress ratio if the membrane stress normal to the mismatch is greater than that parallel to the mismatch.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- ADA400045
Entities
People
- Robert H. Johns
Organizations
- National Aeronautics and Space Administration