连续索在接触点处滑移时会受接触点摩擦的影响,导致连续索在接触点两侧索力不相等。张拉连续索施加预应力时,接触点处的摩擦力使远离张拉端的索段预应力存在一定程度的损失。针对索在接触点处滑移时的摩擦问题,该文采用有限质点法,将连续索离散成相互联系的质点集合,质点间通过索单元连接,滑移索单元内力根据接触点力传递系数和索单元原长不变原则求解。该文推导了考虑接触点摩擦的滑移索单元内力求解公式,提出了索滑移判定准则,并给出了接触点力传递系数计算方法,通过自编程序对算例进行计算分析,验证了考虑接触点摩擦的滑移索单元的正确性和合理性。
A special joint named contact joint is designed to allow the continuous cable to slide through, while the friction inside the joint will cause unequal cable force on each side. When prestress is applied, the friction will hinder the flow of the cable force and lead to loss of prestress. Finite particle method (FPM) is applied to the cable sliding analysis considering the frictional effect, which discretes the continuous cable into a set of finite particles connected by the cable element. The force of sliding cable element is derived based on the force transfer coefficient of the contact joint and the original length of the sliding cable. The formulations to calculate the force of the sliding cable element with the friction considered are derived. The criterion is also proposed to determine whether the cable slides. In addition, the contact joint model to calculate the force transfer coefficient is given. To validate the sliding cable element, numerical examples are analyzed by self-coded program. The results demonstrate that the proposed sliding cable element with the friction considered is accurate and rational.