Applied Mechanics and Materials Vol. 611

Abstract: The paper deals with a dynamic analysis of a passive suspension of a working machine horizontal platform and the two configurations of its suspension system. For the individual alternatives the mathematical models are formulated. The rigid horizontal platform is excited in two perpendicular horizontal directions by kinematic excitation, which was acquired by an experimental measurement of the displacements of the working machine cabin. For the arbitration of which configuration is better two criterions were considered. The first criterion was the effective displacement in two perpendicular directions of the suspended horizontal plate and its rotation around the vertical axis. The second criterion was the effective acceleration of the horizontal plate in two perpendicular directions and the angular acceleration around the vertical axis. The numerical simulations shown that the first alternative (marked as A) gives better results in the reduction of vibration.

Abstract: The paper deals with a design and simulations of segment for hyper-redundant manipulator. In the paper 6-DOF manipulator segment, which consists of pneumatic and electromagnetic actuators, is designed. CAD model of the segment is introduced and basic parts are described. The basic motion is reached by pneumatic actuator which works through the rubber bellows and it utilizes their expansion properties. Main focus of the study besides segment design is analysis of rubber bellows. From this reason FEM analysis is done in software SolidWorks. In the conclusion the results are discussed.

Abstract: This article deals with the influence of optimal actuator and sensor placement on the active control of thin-walled mechanical systems. The approach used for optimal actuator and sensor placement is based on the evaluation norms and. The optimal actuator and sensor placement satisfied the requirements on the controllability, observability and spillover prevention. The investigation of the optimal placement of actuators and sensors is demonstrated on the active vibration of the thin-walled two dimensional mechanical systems.

Abstract: The paper deals with the application of numerical computational tools for the hysteretic curve identification using Karray-Bouc and Ramberg-Osgood models. The Karray-Bouc model parameters will be determined from Ramberg-Osgood model and Manson-Coffin curve parameters. Using special MATLAB’s procedures we can calculate dissipative (hysteretic) energy density per cycle and express Manson-Coffin curve in energy version.

Abstract: The paper describes an algorithm for automatic compilation of equations of motion. Lagrange equations of the second kind and the transformation matrices of basic movements are used by this algorithm. This approach is useful for computer simulation of open kinematic chains with any number of degrees of freedom as well as any combination of bonds.

Abstract: In the paper the principle of welding simulation is presented and the methods of solution of phase transformation are described. The first part characterizes elementary equations of heat transient solution, boundary conditions during welding simulation (prescribing moving heat flux, convection, radiation). The methods of phase transformations’ solution are described for diffusion processes as well as diffusionless processes.

Abstract: The paper reports on two specific research activities devoted on the one hand to detailed finite element simulations of glued timber beams with emphases on random nature of the modulus of elasticity and, on the other hand, to destructive testing of a set four glued timber beams having structural dimensions. While the stochastic simulations were founded on the knowledge of probability density distributions of the modulus of elasticity acquired from non-destructive testing of local moduli from 3600 regularly spaced indentation measurements, the destructive testing of beams in four-point bending aimed at providing information to be used a-posteriori in improving the original predictions in the framework of Bayesian statistics. In this regard the non-destructive testing together with stochastic simulations of beam deflections is assumed to provide prior information to be updated in the second Bayesian step. This, however, will be discussed elsewhere so that only necessary prerequisites are mentioned here.

Abstract: This paper describes the system activity and the importance of autonomous inertial navigation system /INS/ and its implementation to control the robotic arm. The article further introduces the execution of DC motor regulation utilized for the positioning of a rotary positioned arm. The motor control comprises the current regulation, angular velocity and the rotation of the motor shaft fixed to the arm regarding the required angular change course of the arm rotation. The regulation structure of the DC motor is carried out in MATLAB/Simulink programme. The arm movement is investigated via mathematical model and virtual dynamic model formed in MSC ADAMS programme.

Abstract: As a result of a large number of optimising problems, the classification of these problems is essential in the analysis of a given task. One of the parameters significantly affecting the speed and effectiveness of the solution is the correct choice of the optimising variables. We start from the fact that not all the optimising variables have the same influence on the selected objective functions. The goal of the paper is to present a sensitivity analysis which will exclude optimising variables of lower influence and select parameters which will serve as design variables in subsequent optimising analysis.