Applied Mechanics and Materials Vol. 245

Abstract: In this paper, we attempt to study the influence of the bushings (compliant joints) on the static behavior of the guiding system used for the rear axle of the vehicles. In fact, we are interested to determine the difference in behavior between the compliant model (with bushings) and the rigid model (bushings modeled as spherical joints) of the axle guiding mechanism. The static model, in which the car body is attached to ground, is a constrained, multi-body spatial mechanical system, in which the bodies are connected through geometric constraints, compliant joints, and force elements. The external loading is made by vertical forces applied to the wheels, in stationary regime. The study is made for the general groups of guiding mechanisms, with M=1 and M=2 degrees of mobility, by using the MBS (Multi-Body Systems) environment ADAMS of MSC Software.

Abstract: Particulate composites with polymer matrix and solid fillers are one of important types of materials. Generally, these materials are usually used as construction materials, high-performance engineering materials or protective organic coatings. The main aim of a present paper is an estimation of the micro-crack behavior in the particulate composite with non-linear polymer matrix. The polymer matrix filled by magnesia-based mineral filler is investigated by means of the finite element method. A non-linear material behavior of the matrix was obtained from experiment as well as properties of mineral filler. Numerical model on the base of representative plane element (RPE) was developed. The results show that the presence of interphase between particle and matrix can improve fracture toughness of polymer particle composite through debonding process. The conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in particulate composites with respect to interphase.

Abstract: In This study , the large amplitude vibration analysis of laminated composite beam under thermal stress with axially fixed ends is investigated with symmetric and asymmetric layup orientations by using the Rayleigh–Ritz (R–R) method. An exhaustive set of beam boundary condition are studied, namely, hinged-hinged, clamped-clamped, hinged- clamped, hinged-guided and clamped-guided beam in order to prove the efficacy of the present formulation. The composite beam is studied in this paper based on Euler-Bernoulli assumption together with von-Karman’s strain-displacement relation. The simple and efficient closed-form solutions are obtained for the nonlinear harmonic radian frequency as function of central amplitude of the beam using the R–R method. Comparison between results of the present study and those available in literature shows the accuracy of presented closed-form solutions.

Abstract: The paper presents the dynamic analysis of a steering mechanism for a road vehicle, considering the deformability of some elements, such as the steering tie rods. Both the steering and suspension mechanisms were analysed form structural point of view. The kinematic scheme of the assembly was done, followed by a study of their parts and kinematic joints. Then, there was calculated the degree of mobility of the mechanism. The dynamic analysis was approached in case of a stationary vehicle. Considering the geometry of the real model, it was designed the 3D model of the mechanisms assembly. Respecting the positioning on the vehicle, the model was exported to the Adams View software, where the components were assembled, defining the kinematics joints. The values obtained by simulations are compared to those obtained by experimental means. Also, results can be used to optimize aspects of the mechanical system. Finite element analysis was performed to study the contact stress distribution of the rack and pinion gear, considering wheels-road contact and also the friction from the spherical and cylindrical joints of the mechanism. The rack and pinion gear was defined by coupling the rotational motion of the pinion with the translation of the rack.

Abstract: An Intelligent Integrated CAD system applied in mechanical engineering design for selection, calculation and design embodiment of shaft-bearing-gear is presented in the paper. The CAD activities in correlation with the expert system are defined according to a given expertise domain, design of mechanical systems, which is supposed to take into account and operate with two information type: knowledge and data. Final results and concrete example are performed using CAD/CAE/CAM software, CATIA environment. Knowledge and databases processing for application presented in this paper use specific programming environment expert systems, Prolog – Flex. For user interface Visual Basic programming language is used, and Excel for data and knowledge base, which integrated in CATIA environment. Data transmission between the two performance programs CATIA and Prolog is made through the Excel files

Abstract: Nowadays system requirements are set up and evaluated in various manners. When determining an item technical state, there are many options available. However, in order to specify the state and the condition of a system, we choose one off-line approach. The paper deals with mathematical processing, monitoring and analyzing oil field data. Such data comes from the laser spectrography within tribodiagnostic oil tests. When analyzing oil data, we apply mathematical methods based on the analyses and calculations of time series. It is expected to get the results which will help to improve maintenance policy, life cycle costing and operations. Due to the fact that the data sample has been classified as fuzzy and uncertain, the FIS (Fuzzy Inference System) is used.

Abstract: The intention of this paper is to give some methodical approach in Key Performance Indicators for Manufacturing. Within this it covers the defining of Key Performance Indicators (KPI) and Manufacturing Execution Systems (MES). The purpose is to analyze the influences of equipment, personnel and inventory to the production process and how to apply them in making decisions. This paper gives an overview about definition of Manufacturing Execution Systems (MES) and the area of standardization of object models. The KPI for the manufacturing operations management include the areas personnel, equipment, inventory and production process. It contains also a collection of key performance indicators (KPI) to be used in the area of production control and monitoring to assess and define the targets of production processes.

Abstract: This paper explains the necessity of implementing Operations Management Software (OMS) in SCADA systems, by highlighting the benefits of OMS in water and wastewater plants. The modern approach for implementing this kind of system in a Service Oriented Architecture (SOA) is also presented, with examples of existing systems.

Abstract: The drive of the transport machine in extreme conditions should provide high reliability and durability. For this purpose the tooth gearing should have constant gearing of cogwheels. In a number of patents transmission in the form of the hydraulic converter and not switched tooth gearing is presented. However the hydraulic converter considerably complicates transfer and reduces its reliability. Transmission of extreme transport technique should have a simple design and control and to meet extreme requirements. It is expedient to use not switched adaptive tooth gearing based on a phenomenon of mechanical power adaptation. The present work is devoted working out and a theoretical substantiation of effective adaptive transmission for the transport technique working in extreme conditions.

Abstract: This paper presents the experimental procedure of cutting forces measurement, results of the experimental research and their interpretation for the milling of titanium alloys comparing to other hard alloys. Furthermore, there are established the polynomial regression functions to determine the cutting forces depending on the cutting regime parameters: cutting speed, feed rate and depth of cut.