Adrian Sorin Rosca

Design of a Test Rig for Vehicle Stabilizer Bar Fatigue Study

In this paper the design, experimental and numerical simulation of a test rig for stabilizer bars fatigue resistance study is presented. A virtual CAD of the test rig is developed, for design and simulation purposes. A dynamic simulation model is developed in ADAMS software, to study the stabilizer bar durability. Strain gauge transducers are used to measure the deformations of the stabilizer bar.

Design, Numerical Simulation and Manufacturing of a Powered Wheelchair

This study presents the authors research to develop a powered wheelchair for disabled people. The wheelchair is intended mainly for use in buildings area. The proposed solution for the wheelchair propulsion uses a chain transmission for each wheel and two motors. The benefits of the chain transmission, from ergonomic aspect is that they ensure the wheelchair folding for easy transportation with a vehicle and allows the motors placing in the front, thus providing better stability to access ramps and for climbs. From dynamic perspective, implementation of a chain transmission in the wheelchair propulsion, improves dynamic performances by multiplying the torque. Simulations performed in ADAMS reveal optimal performance of the wheelchair. Based on the proposed design of the wheelchair a prototype is manufactured and are presented experimental obtained results for motion analysis.

Nonlinear Analysis of Temperature during Orthogonal Turning

In this paper orthogonal turning processes are analyzed for different depth of cut. The temperature during the machining is analyzed. The nonlinear dynamics of the orthogonal turning are characterized with fft, phase plane, time delay, embedding dimension and largest Lyapunov exponents. The Lyapunov exponents can be used as a dynamic stability index for the system. The largest Lyapunov exponents for two different depth of cut show the chaotic behavior of the system.

Experimental Validation of an Exoskeleton for Motion Assistance

In this paper experimental investigations concerning the prototype validation of an exoskeleton for human gait rehabilitation are presented. The proposed exoskeleton is intended for human legs motion assistance, being a low cost solution. The exoskeleton provides motion assistance for human hip and knee joint. The experimental gait analysis of the exoskeleton and assisted human subject is performed with goniometers sensors. These sensors are attached to the exoskeleton hip and knee joints and measure the angle variation. The results obtained for the exoskeleton motion are compared with those obtained in case of a healthy human subject. Angular variation corresponding to a step, as a comparison for human and exoskeleton joints is performed. The conclusion is that the designed exoskeleton is proper for human gait motion assistance, because the joints motion is comparable with the human subject.

Modal-Dynamic Analysis of the Steering Mechanism on a Vehicle

The present paper aims to identify the dynamic feedback of a steering mechanism in a vehicle, mainly under stationary conditions. The modal – dynamic analysis was established by applying two methods, the experimental method and the finite element modelling. For the experimental results concerning the proper frequencies of the steering box and of the tie rods assembly, a method of excitation with a measured and controlled linear momentum (impulse) force was implemented. The modal-based analysis aimed to measure the proper frequencies and the proper vibration modes. Therefore, the harmonic analysis obtained by using the finite element method is applied in order to determine the frequency variation diagrams of some nodes displacements, from some of the elements of the mechanism. Furthermore, the applied analysis seeks to identify the critical frequencies and the corresponding phase angles by investigating the displacements, the strains and the stresses of the mechanism elements, which correspond to critical frequencies and phase angles.

Thermal Source at Turning Allied Steel

The paper presents a method which combines experimental and theoretical approach, to derive an expression for estimating the power of thermal source in a turning process. This method uses a finite element mesh overlapped on infrared images (obtained from the cutting process), in order to extract the nodal temperatures corresponding on. A reverse formulation for a finite element analysis is used, knowing the nodal temperatures and boundary conditions, and deriving the thermal load which produces the measured thermal distribution. This experiment has concentrated to allied steel.

The 3D Virtual Model of a Classical Hip Joint Prosthesis

In this paper were presented the main steps for defining a virtual prosthetic hip. The elements of the classic hip prosthesis were generated, one by one, using direct measurement method. These elements were included in the biomechanical hip system. The entire model was divided in finite elements. Starting from this 3D model, the goal of the research is to determine new geometries and optimized solutions for an innovative hip prosthesis.

ARX Development for SQL Connection with Mechanical Desktop

Abstract The paper explores one of the most useful and interesting facilities for a CAD system: the bilateral relation with a database. This connection allows the development of a new tire in data management, establishing a permanent relation between graphic information (handled by a CAD system), and non graphic information (handled by a database manager). The novelty of the paper consists in exposing the internal mechanisms of data management, which are the basis of handling foreign data in Mechanical Desktop environment. All the considerations are done for version 6 of Mechanical Desktop, in connection with the version 15 of ARX library.