Dynamic Response of a Beam Including the Mass Effect of the Moving Loads

이동 하중의 질량효과를 고려한 보의 동적응답

The system such as railway bridge can be modelled as the restrained beam with intermediate supports. This kind of structures are subject to the moving load, which has a great effect on dynamic stresses and can cause sever motions, especially at high velocities. Therefore, to analyze the dynamic characteristics of the system due to the moving load is very important. In this paper, the governing equation of motion of a restrained beam subjected to the moving load is derived by using the Hamilton's principle. The orthogonal polynomial functions, which are trial functions and satisfying the geometric and dynamic boundary conditions, are obtained through simple procedure. The dynamic response of the system subjected to the moving loads is obtained by using the Galerkin's method and the numerical time integration technique. The numerical tests for various constraint, velocity and boundary conditions were preformed. Furthermore, the effects of mass of the moving load are studied in detail.

본 연구에서는 스프링힌지, 클램프, 단순지지, 탄성지반, 다수의 병진 및 회 전스프링 그리고 중간지지점의 조합으로 구성되어 있는 보에 대하여 우선 Hamilton원 리에 의하여 정확한 보의 특성방정식을 유도하고 모든 경계조건을 만족하는 직교다항 식을 구한 후, 스프링, 댐퍼로 구성된 여러개의 질량이 일정한 속도로 이동할 경우에 대하여 Galerkin방법과 수치적분 방법을 사용하여 동적응답을 구하였다. 또한 구속 조건 및 경계조건이 변함에 따라 동적응답에 미치는 영향을 연구하였다.