Title:
Realistically Assessing Load Severity on Concrete Foundations and Mounting Systems for Large Reciprocating Compressors
Author(s):
Anthony J. Smalley and P. Joe Pantermuehl
Publication:
Structural Journal
Volume:
96
Issue:
5
Appears on pages(s):
774-780
Keywords:
compression; finite element analysis; loads (forces); stresses
DOI:
10.14359/731
Date:
9/1/1999
Abstract:
This paper addresses the loads generated and transmitted by large reciprocating compressors to their concrete foundations. It emphasizes the need to quantify (realistically) the loads that must be transmitted across the tie-downs connecting a compressor to its foundation, and it identifies the significance of these loads to the integrity of tie-downs and concrete. It considers gas forces induced by the compression pro-cess, unbalanced inertia forces induced by reciprocating and rotating motion of compressor components, and shows the importance of con-sidering forces from individual throws and cylinders. The paper doc-uments that assumptions regarding compressor frame flexibility strongly influence predictions of tie-down forces, and that the most common assumption (zero flexibility) can grossly underestimate these forces. The alternative assumption of a fully flexible frame provides conservative (high) force values. Finite element analysis of the com-bined compressor frame and concrete foundation system provides the most accurate load values but requires a significant increase in com-putational complexity. The paper quantitatively compares these alternative assumptions, provides a basis for making a choice, and shows how predicted loads influence tie-down design parameters and concrete stresses.