Design of the optimal control for the active suspension

The main purpose of the suspension is to minimize vertical acceleration. Through this paper we aim to analyze two PID and LQR control techniquesto reduce system vibrations. The active system will be compared to a passive system using two types of profile. Matlab / Simulink software is used to evaluate the performance of the two controllers using a system with two degrees of freedom. The analysis shows that we can control the suspension system using the two techniques to improve the comfort and safety of the vehicle.

Brief review of metamaterials and auxetic materials

This paper aims to provide a comprehensive review on auxetic materials and structures, including various types of cellular auxetics, natural and artificial auxetics, metallic auxetics, multi-material and composite auxetics. A material engineered to have aproperty that is not found in naturally occurring materials is the metamaterial (meaning"beyond" from the Greek word μετά meta, and "material" from the Latin word materia) made from assemblies of multiple elements shaped from composite materials such as metals and plastics. They have exceptional properties, derive from their geometrical shape rather than directly from the behavior of the base materials, in terms of mechanical response, energy absorption and, heat transport performance.One of the most studied species of mechanical metamaterials is the auxetic materials, a type of mechanical metamaterial with a negative Poisson’s ratio (which shrink transversely under longitudinal compression and expand transversely under longitudinal tension). They consistof numerous hinge-like cells that are joined together. The cells have a re-entrant geometry, i.e. under pressure, they expand in lateral direction.Superior and unusual properties of auxetics are presented and some existing or potential applications are summarized. Accompanied by uncommon deformation pattern under compression and tension, auxetic materials and structures are endowed with many desirable material properties, such as superior shear resistance, indentation resistance, fracture resistance, synclastic behavior, variable permeability and better energy absorption performance.

The collapse modesclassification of tubes with different shapes of the cross-section

In this paper, the authors present the collapse modes classificationof tubes under axial loads.This topic is sensitivebecausepollution requirements are becoming more stringent and the emissions value ofCO2should be reduced. Therefore, to achieve this, modern vehiclesmust have a lower weight.The condition that a vehicle has a lower weight and high performance is that materials should have a lower weight and at the same timeahigh degree of protection. In case of a collision, the dimensions of the cockpit shouldn’t change, hencethe energy is consumed by the controlled deformation of the sacrificial structures. These sacrificial structures are defined by tubes/structures with closed profiles.

Overview on the Use of Natural Gas in Spark Ignition Engines

As air pollution and global warming become a priority in sustainable mobility, the evolution of vehicles is facing many regulations that are becoming increasingly stringent in terms of reducing greenhouse gas (GHG) emissions, forcing the automotive industry to search for solutions to make their products more environmentally friendly. In this environmental and legislative context, considerable attention has been given to natural gas (NG) in spark ignition (SI) engines. Many studies have been conducted to assess the impacts of NG use on engine operation.This overview paper discusses some aspects of recent studies on Natural Gas(NG)production, its physico-chemical properties, and also, on the influence of the use of compressed natural gas (CNG) in SI engines: combustion characteristics, performance, and emissions.

Overview on the Cylinder Deactivationtechniques

"Temporary downsizing" in the form of deactivation of the cylinders is used as an attractive compromise, as it allows to improvefuel consumptionandat the same time it allows sufficient power reserve to meet the requirements of the driver, maintaining driving pleasure as well as comfort regarding noise and vibration levels.The paper aims topresent an overview on the cylinder deactivation techniques focusing on the stakes and challenges related with their implementation.

An overview on metal-oxide catalytic converters

Diesel vehicles produce exhaust gases that include nitrogen oxides (NOx), carbon monoxide and hydrocarbons.A major environmental problem is the elimination of nitrogen oxides, as they are major air pollutants. Global restrictions on NOx emissions from fuel combustion have been imposed. Efforts have been made to develop catalysts for the selective catalytic reduction of NOx. In this paper is presented the types of catalytic converters used nowadays for dissipate emissions and selective catalytic reduction.

Analysis of interactions between participants involved in the design of an equipment of monitoring the microclimate conditions in the automotive industry

This paper presents a series of studies realized on a design experiment made by a multidisciplinary team from the Faculty of Mechanics and Technology of the University of Pitesti. The design experiment consisted in the development of an equipment for monitoring the microclimate conditions at a workstation from theautomotive industry. The participants at this experiment had the following roles: CAD / CAM specialist, IT and electronics specialist, ergonomics specialist and a team leader. The experiment was observedand recorded in order to analysethe interactions between the participants and the effects of these interactions on the development and performance of the studied design process.

Microstructure and phase composition of surface layers formed on aluminium alloys by plasma electrolytic oxidation

This paper presents elaboration and structural characterization of surface layers formed on aluminumalloys by plasma electrolytic oxidation (PEO). The electrolyte is a mixture consisting: sodium metasilicate and sodium hydroxide. The coatings obtained by PEO were investigated with: scanning electron microscopy (SEM) with Energy dispersive X-ray spectrometer (EDX) and X-ray diffraction (XRD)techniques.

Design and construction of an experimental test bench for the study of a mechanical system used for coupling power sources

This study investigates the experimental test bench specially created fortestingaplanetary mechanism with two degrees of freedom in the configuration of hybrid electric vehicle powertrain. For the experimental study, it was necessary to build a test bench that consists of a metal frame on which other mechanical and electrical components are positioned: the mechanical coupling system, the thermal engine, a three-phase electric motor and an alternator. The test bench can simulate road load, during which time it is measured with the help ofa torque sensor the mechanical moment developed by the electric motor used in this configuration.

The determination of the mechanical friction work in a cam –follower couple of complex cam mechanisms. Part I-theoretical aspects

In thispaper we arepresenting theoretical aspects regarding the determination ofthe mechanical friction work presentedin a cam-follower couple, in the case where the follower has a plane parallel movement. An articulated quadrilateral mechanism itis cinematically anddynamically studied, where the connecting rod is actioned by a rotation cam. For showing the relative movement of the contact point on the cam and on the follower, a zero-dimension ring is inserted between the cam and the follower. The expression of the mechanical work is obtained after solving the cinematic and dynamical analysis of the complex rotation cam mechanism. The value of the mechanical work is obtained by integration. The conclusions are presented in the end of the paper and it is mentioned that in a future paper, a numerical application will be made for illustrating the calculation algorithm.