the partial differential equations for water flow and solute transport in a two-dimensional saturated domain are rendered discrete using the finite difference technique; the resulting system of algebraic equations is solved using a dynamic programming (dp) method. the advantage of the dp algorithm is that the problem is converted from solving an algebraic system of order nc(nl-1) nc(nl-1) into...

Online approximation of the optimal station keeping strategy for a fully actuated six degrees-of-freedom marine craft subject to an irrotational ocean current is considered. An approximate solution to the optimal control problem is obtained using an adaptive dynamic programming technique. The hydrodynamic drift dynamics of the dynamic model are assumed to be unknown; therefore, a concurrent lea...

In this research, vibration control of national engine (EF7) using active mounts is studied for two different mounting layouts. The first layout is based on the current engine mounting of national engine (system of three passive mounts), but the hydraulic mount is substituted by an active mount. The other mounting layout contains 4 mounts, 2 of which are active ones and the others are passive m...

In this study, the finite element model updating was simulated by reducing the stiffness of the members. Due to lack of access to the experimental results, the data obtained from an analytical model were used in the proposed structural damage scenarios. The updating parameters for the studied structures were defined as a reduction coefficient applied to the stiffness of the members. Parameter v...

Dynamic modeling of osteoarticular system is necessary because the exertion of various actions and natural physiological movements are essentially dynamic. The wide mobility of human body leads to the necessity of modeling the osteoarticular system as a mechanism with a large number of degrees of freedom. The differential equations system obtained are very complex and assume numerical integrati...

In general, joints are assumed without clearance in the dynamic analysis of multi-body echanical systems. When joint clearance is considered, the mechanism obtains two uncontrollable degrees of freedom and hence the dynamic response considerably changes. The joints’ clearances are the main sources of vibrations and noise due to the impact of the coupling parts in the joints. Therefore, the syst...

A gear transmission dynamic model for the gear dynamic contact loading, dynamic contact stress state and dynamic contact strain state analysis is presented. A dynamic model of the transmission with four degrees of freedom is used. The transmission is analyzed using nonlinear finite elements contact formulation, using a novel software modules developed by the author used for the generalized anal...

This study presents a new approach for physical and material modeling of space frame-raft-soil system. The physical modeling consists of a modified Thimoshenko beam bending element with six degrees of freedom per node to model the beams and columns of the superstructure, a modified Mindlin's plate bending element with five degrees of freedom per node to represent the structural slabs and raft, ...

Underactuated manipulators are robot manipulators composed of both active and passive joints. The advantages of using such systems reside in the fact that they weight less and consume less energy than their fully-actuated counterparts, thus being useful for applications such as space robotics. Another interest reside in the reliability or fault-tolerant design of fully-actuated manipulators. If...

in this article, vibration analysis of an euler-bernoulli beam resting on a pasternak-type foundation is studied. the governing equation is solved by using a spectral finite element model (sfem). the solution involves calculating wave and time responses of the beam. the fast fourier transform function is used for temporal discretization of the governing partial differential equation into a set ...