This paper presents ways for modeling the unilateral contact with friction between solids in order to simulate a collection of polyhedrons during evolution. In a first stage 2D problems of polygon collections are explored, then the friction conditions are easy to take into account by several available equivalent modeling. In a second stage 3D problems of polyhedron collections are considered. The aim of this paper is to propose efficient algorithm to solve the 3D numerical problems in granular material simulations.

Modern design techniques primarily consist of finite element analysis of the vehicle body in a computational media. In this study, an actual double-deck bus body of domestic production has been modeled in three-dimensions by means of IDEAS program in order to calculate its fatigue strength. In other words, an approximation algorithm has been developed to obtain service loads. The effects of dynamic and static loads on the bus body have been calculated and included to the FEM analysis. As a new approximation technique, during the service life of a vehicle under dynamic loads (straight good road, straight bad road, cornering bad road and singular obstacle road) arising from the road conditions as taking into account, load spectrum has been constituted. In the design spectrum that has been utilized in our calculations, considering the equivalence damage effect rule, instead of using straight good road conditions, other fifty percent of forces that have been mentioned above, accepted as hundred percent of dynamic and static forces caused by bad road conditions acting on the bus body. As a result of this study, the calculated results have been compared to the theoretical and experimental data taken from literature review. It can be seen that this approximation technique that we used in our calculations can be used for this kind of fatigue analysis of vehicle components or bodies.

There are extremely important applications to investigate the control of contact between the end-effectors and the object. During controlling an object, static or in motion, the robot arm should not be damaged. Forces are important in such conditions. The forces between the end-effectors and the object have to be controlled. The motion of the robot arm changes forces. Thats why, to control forces, a force kontrol algorithm must be developed. Previous conventional force control algorithms could not control the robot effectively by only considering the variation of working environment. In this study, a control algorithm strategy to achieve the desired interactions forces between the robot end-effector and the environment during contact tasks, has been developed. The surface of the object and robot are very stiff, thus contact spring coefficient Kc is very large, because of this Kc effect, the results of the forces simulation results, but we get suitable results. Study include, modelling robot arm, evaluating measured forces during contact and constructing a suitable force control algorithm, dynamics, kinematics and simulation results. In this study, we used impedans control which the surface of the object is very stiff, as known as impedance control does not try to track position and force trajectories directly, but rather to regulate the dynamic relationship between the contact forces and manipulator positions, namely the mechanical impedance. Impedance control focused on the design of a robot’s dynamic behavior as seen from the environment. In this control strategy, no hardware or software, switch is needed in the robot’s control system when the robot travels from the free motion space to the constrained space. The force feedback loop closes naturally as soon as the robot interacts with the environment, which changes the robot’s impedance as seen from the environment. By controlling the manipulator positions, and regulating their relationship to the contact forces, the manipulator can be controlled to maintain appropriate contact forces.