The dynamic similitude design of a thin-walled cylindrical shell by considering the strength requirement

Abstract

In designing the test model of thin-walled cylindrical shells, geometrically distorted models are widely used. This study investigates a method of designing a distorted cylindrical shell model by considering the strength requirement, which means the test model should reflect the strength situation or even failures of the prototype. The significance of this study is that it provides an acceptable process which guides the design of test models. First, governing equations are employed to derive the scaling law of the natural frequency. The harmonic response is calculated in order to obtain the scaling law of the vibration response amplitude. As the study is based on governing equations of elastic cylindrical shells, only elastic behavior is discussed. Then considering the different materials’ ultimate stress, an excitation force ratio is defined. An applicable size interval is investigated and the range of the excitation force is obtained. Finally, an aluminium alloy cylindrical shell is used as a prototype and a NO. 45 steel scaled down cylindrical shell is used as a distorted test model. The accuracy of the prediction is verified by using simulation data.