| Scale models are mostly used in shaking table test, and the qualities of most models are inadequate. In shaking table test, we usually enlarge the acceleration to meet the similarity between models and prototype structure in the earthquake. But just because of the inadequate mass, the vertical compressive stress of constructions is also inadequate. This is the gravity distortion. It can lead to premature destruction of the vertical component, early degradation of structural stiffness, and changing of the structure's failure mode. In other words, model structure can't be a true reflection of the failure process of the prototype structure. This paper proceeds from shaking table test, for the purpose of improving the existing similarity relations and designing similar models. We hope to improve earthquake test technology under considering the gravity distortion.In order to eliminate the adverse effects of gravity distortion, we design two identical models for shaking table test in this paper. One of models is full weight, not enlarging the peak acceleration. Another is less weight, enlarging 3 times of the peak acceleration. We observe the two models differences of failure process. We find that the two models destructions are different by the shaking table test. So the effect by gravity distortion can't be ignored.We use ANSYS software to simulate the two models. When the acceleration enlarges 3 times, the internal forces of the two model components are not similar. But if the two models acceleration is equal to each other, the internal forces of full weight-model's components are 3 times of less weight-model's. So in this paper, we summarize the rules between the axial force ratio, steel strength, steel areas, the elastic modulus of concrete and the ultimate bearing capacity of components. We put forward 2 situations and illustrate the design method of model components, so that the two models under the same peak acceleration are similar to each other.
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