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At macroscopic level, traffic can be described as a continuum flow. Lighthill Witham and Richards (LWR) have developed a traffic flow model based on the fluid dynamics continuity equation, which is known as the first order LWR traffic flow model. The resulting first order partial differential equation (PDE) can be analytically solved for some special cases, given initial and boundary conditions, and numerically using for example the finite element method (FEM). This paper makes use of the Galerkin FEM to solve the LWR model with constant speed. The road is divided into a number of road segments (elements) using the Galerkin FEM. Each element consists of two nodes. Each node has one degree of freedom (d.o.f.), namely the traffic density. The FEM provides a solution for the degrees of freedom, i.e. traffic densities of each node. The resulting simultaneous equations are solved at different time steps using the Euler backward time-integration algorithm. In Belgium and also in the Netherlands, there is a special technique that can be used in order to prevent traffic jams and increasing safety in situations with high volume of cars on the roads, i.e. block driving. It is a technique where cars drive in groups by order of the police when the roads are crowded. In this paper block driving is used as a practical example of the LWR model with constant speed. Thereby, it is simulated using the Galerkin FEM and the results are compared with the analytical solution. The FEM gives good results providing that: the road segments and time steps are small enough. A road with length 5000 m, constant speed of 25 m/s, segment length of 100 m and time steps of 1 s gives good results for the studied case. At points of traffic density rate discontinuities, depending on the road segment size and time step size, the Galerkin FEM is accurate and requires reasonable computational effort. From the research work carried out in this paper, it is found that the Galerkin FEM is suitable for modelling traffic flow at macroscopic level. The element size and time step size are important parameters in determining the convergence of the solution in case of discontinuities in traffic density rate. Although this paper considers the case of constant speed, the technique can be extended in the future to include the case of non-constant speed, i.e. speed as a function of traffic density. [ABSTRACT FROM AUTHOR]

The paper presents a dynamic model considering the human upper limb as a mechanic system with 6 degrees of freedom where the segments are moved by their own weight forces. The bones were modeled in Solid Works, the model of the upper limb obtained being very close as form to the real one. Based on this model, the calculus of mass proprieties was made. The differential equations of velocities obtained were solved using Lagrange formalism with help of Matlab programs. A dynamic model must provide a good approximation of total weight and mass distribution as well as transmissibility and amortization proprieties for bones, muscles and joints. [ABSTRACT FROM AUTHOR]

In this paper we present some results obtained from a dynamic response analysis of a mobile mechanical system, in two cases, when the elements are considered as a rigid ones, and when these elements are considered deformable. For both situations we propose for analysis the Newton-Euler formalism completed with Lagrange's multipliers method. The obtained mathematical models were tested on a wiper windshield mechanism which has a spatial motion. Combining the experimental analysis with the dynamic inverse analysis we obtain the connecting forces variation laws from the mechanism's joints. These forces will constitute the loading base for finite element modeling of the all mechanical system. Through finite element modeling we were obtained the variation laws depending on time, for cinematic parameters in dynamic regime. [ABSTRACT FROM AUTHOR]

The paper presents an original homogenization method to predict the elastic properties of multiphase pre-impregnated composite materials like Sheet- and Bulk Molding Compounds. The upper and lower limits of the homogenized coefficients for a 27% fibres volume fraction SMC are computed. It is presented a comparison between the upper and lower limits of the homogenized elastic coefficients of a SMC material and the experimental data. The estimation model used as a homogenization method of these heterogeneous composite materials, gave emphasis to a good agreement between this theoretical approach and experimental data. [ABSTRACT FROM AUTHOR]

This paper is concerned with a mathematical and numerical study of the effect of gas entrapment on liquid dynamics in a closed-end horizontal capillary. This problem is important in order to understand how the presence of a gas inside the capillary can influence the dynamics of capillary flows and the non destructive test procedures carried out through liquid penetrant testing. In this context, by considering the most relevant approaches in modeling the gas entrapment inside a cylindrical capillary, some numerical simulations are carried out in order to deduce peculiar features arising in such a problem. [ABSTRACT FROM AUTHOR]

The paper presents a new testing stand for antifriction bearings, suitable for all types of rolling and sliding bearings, especially for those having small diameters and operating at high rotation speeds. The design of this stand occurred as a necessity of additional equipment to the research endowment required by several research projects developed in partnership by the author's institutions. It also can be used in proper conditions to test artificial joints for knees or elbows, consistent at model level with cylindrical bearings. [ABSTRACT FROM AUTHOR]