MOMENT DISTRIBUTION METHOD although a very powerful tool is not used by any computerized pipe stress program.
CAESAR like like many other Pipe Stress Programmes used the STIFFNESS method to solve the equations. I hope you are aware of the FLEXIBILITY and STIFFNESS methods of analysis.If you are not, please read the book MATRIX ANALYSIS OF STRUCTURES by WEAVER.
For a beam element, which CAESAR II uses, the stiffness coefficients can be computed easily from moment-curvature relations of a beam ( shear deformation i.e. Timoshenko Beam Theory is not considered in this relation). For complex elements like Plates, Shells etc, the more rigorous Finite Element Analysis method ( the stiffness method of analysis that you find in text books on Matrix Structural Analysis is sort of an exact analysis, exact in the sense of "exactness" of the elementary beam theory).If the interpolation functions used in FEA are the same as they are in the "exact solution"the the two approaches give same results.So this approach although theoretically a Finite Element Analysis , is not typically called so.The matrix structural analysis can be considered to be a part of development of the more rigorous FEA .
Rigorous FEA goes by the "FUNCTIONAL APPROACH" of VARIATIONAL CALCULUS.
One suggestion: To understand the STIFFNESS and Flexibility methods, first get the concepts clear on Elemenraty Beam Theory and the "SLOPE-DEFLECTION" relations.
Regards
Anindya
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anindya