The paper presents the mathematical model of a pipelay spread. In the model, elasto-plastic deflections of the pipe, its large deformations and contact problems are considered. The modification of the rigid finite element method (REFM) is used to discretise the pipe. The problem is analyzed in two stages. First, the quasi-static problem is considered. The tip of the pipe is pulled from the reel to the tensioner. Then, dynamic analysis (during ordinary work) of the pipelay spread is carried out. Some results of numerical calculations are presented.

The paper presents a model of a car with special attention given to the drive system. Two possible drive systems were considered: with standard differential and independent drive of each wheel by means of an electric motor. In both cases, flexibilities of live axle shafts have been taken into consideration. A 3D model of the car was assumed. The model consists of a system of rigid bodies connected one with another by means of elastic-damping elements. The phases of static and kinetic friction were considered in the steering and drive systems. The method of homogenous transformations was used in the mathematical description. The results of computer simulations are presented.