Substructuring is a technique in finite element analysis for solving mechanical engineering problems involving large structures which are too enormous for existing computer hardware and software to handle. This technique involves breaking the system into parts, analyzing the parts, and then re-assembling the total system using selected degrees of freedom from the parts. This thesis also provides a review of substructure theory as a background. The state-of-art involving different approaches of the method is presented . The ANSYS finite element analysis program is used for the case studies of analyzing a container refrigeration unit frame structure. The experimental vibration test results on the structure are used for comparison with the analytical results from the modal analysis of the various case studies. Results from case studies of both the simple models and the complicated container refrigeration unit frame structure all indicate that substructuring by ANSYS renders better solutions than the conventional modal analysis with appropriate numbers of mass master degrees of freedom specified for each substructure. Additional master degrees of freedom are required in substructure dynamic analysis to achieve reliable solutions. Computer time saving is not achievable by using substructuring in ANSYS for dynamic analysis due to the excessive calculations used by the wave front solver for generating each substructure analysis. Computer time saving is only achievable for the cases of analyzing a structure representing repetitive or symmetrical features in geometry .

Library of Congress Subject Headings

Structural analysis (Engineering)--Data processing; Refrigeration and refrigerating machinery--Vibration--Analysis; Structural dynamics--Data processing

Publication Date


Document Type


Department, Program, or Center

Mechanical Engineering (KGCOE)


Torok, Joseph

Advisor/Committee Member

Budynas, Richard


Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TA647 .C54 1992


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