Math. Comput. Appl., Volume 5, Issue 1 (April 2000) – 7 articles , Pages 1-65

Off-highway truck performance and retarder charts are used to calculate number of trucks for different road conditions. Determination of speed of a truck enables calculation of time that will be spent for that road profile. Total cycle time is a parameter, which is crucial from economical point of view for the calculation of number of truck. In this study, Newton Divided Difference method is examined for modeling of performance and retarder chart of mechanical wheel drive truck. The aim is to provide a practical chart modeling manner and base for further truck motion simulation. The approach is coded in C++ and applied to a real overburden stripping mine panel. The reasonable results reveal that the system is convenient for chart modeling and cycle time calculation. Full article

In this paper, we obtained the distribution parameter of a spacelike ruled surface generated by a spacelike straight line in Frenet trihedron moving along a spacelike curve. We show that the spacelike ruled surface is developable if and only if the base curve is a helix (inclined curve). Furthermore, some theorems are given for the special cases which the line is being tangent, the principal normal and binormal of the base curve. Full article

The software package "SCPPBAND" (Self-Consistent Pseudo-Potential BANDs) is developed with the purpose of consecutive realization of micfoscopic solid state theory concepts for the electron subsystem description of multiatomic crystals within the "ab initio" uniform approach and is applied for the fundamental characteristics desciption of the crystals of various classes: BaTiO₃ - perovskite - a representative of the wide-gap dielectrics, PbMoO₄ - crystal with a sheelite structure not being the object of consecutive microscopic calculation previously and GeTe - narrow-gap semiconductor-ferroelectric - a representative of A⁴B⁵ - group. The obtained results are in good agreement with availlable literary and experimental data. Full article

For two-dimensional elastoplastic stress analysis of frictional contact problems an isoparametric quadratic formulation of the boundary integral equation (BIE) method is presented with emphasis on clarity at the expense of efficiency. The overall system of equation is obtained by using multi-domain approach in which the contact conditions are taken into account to couple the different system of equation for each body in contact, Several types of contact interface conditions are covered including Infinite friction (stick), frictionless and Coulomb friction slip. In order to include plastic deformation in the analysis, the initial strain formulation and von Mises yield criterion are used. In order to evaluate internal stress and strain rates the differentiation of the displacement in elementwise manner is adopted with its compulsory modeling of partial (where plastic deformation is expected) domain. Elastic-perfectly plastic, work-hardening or mixed hardening material behaviour can be assumed. An efficient and robust incremental-iterative process is proposed to find the proper contact conditions. For the numerical implementation, isoparametric three-noded line elements are used to represent the boundary and eight-noded quadrilateral domain cell are used for partially modelling interior domain. The proposed algorithm is applied to the heftz-like indentation problem and the results are, where appropriate, compared with the presented results in the literature to confirm its correctness and robustness. Full article

Using free simplicial algebras, it is shown that a free or totally free 2-crossed module can be constructed on suitable construction data in [2]. In this paper 2-crsossed complexes and freeness conditions for 2-crossed complexes are introduced and similar freeness results for these are discussed. Full article

Firstly the Lie point symmetries of cylindrically symmetric homogeneous Nawier equations are obtained. Using the symmetries the general class of similarity solutions are found. The subclass that also satisfies the non-homogeneous system of the medium subject to a singular force is determined. Substituting the subclass into the non-homogeneous system, a system of ordinary differential equations is obtained. The solution of the system satisfying the boundary conditions of Bousssinesq problem gives the exact solution. Full article