Influences of small curvatures on the modal characteristics of the joined hermetic shell structures

From a practical engineering point of view, there is interest in understand ing the influences of small curvatures on the modal characteristics of a pl ate-shell combination. However, research reports in this area are rarely fo und in literature. This paper is the first one to study the influences of s mall curvatures on free vibration of a plate-shell combined structure, cons isting of a circular barrel-like shell and two spherically curved end plate s, using the line receptance concepts and approximate frequency equations o f barrel-shaped shell and spherically curved prate. It illustrates in detai l information about natural frequencies and mode shapes of the combined str ucture under different geometric configurations. Consequently, it provides useful information for setting up criteria for designing hermetic prate-she ll joined structures, such as the hermetic shell of a refrigeration compres sor. The receptance method, which is basically a component mode synthesis t echnique, is adopted as the solution procedure in this study. It predicts t he responses and frequencies of a combined system in terms of the responses and frequencies of its subsystems. This technique, for cases to which it c an be applied successfully, is a powerful tool in creating an understanding of the physics of combined structures. (C) 2000 Academic Press.