Applied Mechanics and Materials Vol. 657

Abstract: Top domains of technology, such as aerospace, nuclear technology, electrical engineering, electronics, energy, require materials and alloys with special properties: superconductivity, superplasticity, high resistance to corrosion, shape memory, exceptional mechanical strength, magnetism, and resistivity. Aluminum bronzes are bronze with very good mechanical and chemical properties, which are factory profiles, strips, bearings, gears, valves, parts and fittings for chemical and food industry, gears, water pump housings, mainly parts corrosion resistant in aggressive environments.

Abstract: Considering that, in Accordance with the Laws of Physics, the Sound Travels only through Elastic Bodies, the Main Characteristic of an Acoustic Material is the Elasticity. Classifying the Metallic Materials in this Regard is Quite Difficult, as the Elasticity is Characterized by more than One Component (static Elastic Modulus, Dynamic Elastic Modulus, Static Elastic Limit, Elastic Limit, Elastic Deformation Linearity, Damping Capacity). Best Acoustic Properties of some Metallic Materials are Widely Used in the Construction of Transducers, Musical Instruments, Bells Etc. for this Purpose, a Study on Three Metallic Materials was Conducted: a Cusn Alloy for Bells, a Cast Aluminum Alloy and a Martensitic Cast Iron. this Study Highlights both the Chemical Composition, Structure, Mechanical Properties and Damping Capacity of Sounds.

Abstract: This paper presents a study of the tribological properties of polymeric composite materials reinforced with unidirectional carbon fibers having stratified structure. Unidirectional reinforces carbon fiber materials are more effective if refer to specific properties per unit volume compared to conventional isotropic materials [. Potential benefits of carbon fibers composite materials are: high resistance to breakage and high value ratios strength/density; resistance to high temperatures; low density and high resistance to wear; low or high friction coefficient. The composites are complex and versatile materials but their behaviour in practice is not fully studied. For instance, polymeric composite materials reinforced with carbon fibers after being investigated in terms of wear, did not elucidate the effect of fiber orientation on wear properties [. Is therefore necessary to investigate the effect of carbon fibers orientation on the friction wear properties of the reinforced composite materials tested to adhesive and abrasive wear. Research work has been done with unidirectional composite materials having overlap 16 successive layers made from a polymeric resin and 60% of carbon fibers. The stratified structure was obtained by compressing multiple pre-impregnated strips, positioned manually. During this experimental work, three types of test samples were investigated: normal, parallel and anti-parallel, taking in consideration the carbon fibre orientation with respect to the sliding direction. The specific wear rate was calculated according to: the mass loss, density, the normal contact surface, the sliding distance and load rating. The friction coefficient is computed function to the friction load and loading value.

Abstract: The paper presents in its first part the need for analysing the functioning of the cardan cross within the cardan transmission, both from the point of view of shape and from the point of view of the material. In the second part there are described the main elements for analysing the test samples, the employed testing machine, as well as the manner of processing the obtained information. The last part contains the conclusions resulted from this analysis..

Abstract: The aim of the research of the experiment was to determine the mechanical characteristics of the composite layered material. There has been two types of experimental tests i.e. test for determining the tensile modulus of elasticity of the material, the maximum voltage and the elongation at break of the material. The second type of test is the flexural test was intended to determine the maximum load that the breaking is produced by bending.

Abstract: This paper presents the results of the profilometric analysis of wear tracks from tribological tests of a composite material made by Diamond Metallplastic GmbH, Germany. This material has a polymer matrix reinforced with Cu, Zn, Sn particles, and various allotropic forms of SiO₂. The material belongs to Multimetall Messing category and is recommended by the manufacturer for repairing brass made parts. This composite material was tribologically tested in dry friction reciprocating conditions, in ball-on-flat configuration, using the tribotester CETR-UMT-2 (Bruker Corporation). The counterpiece was a steel ball. The tests were conducted at normal loads of 20, 30, 40 and 50N, over a distance of 100 m, at an average sliding speed of 3,50 mm/s, at room temperature and relative humidity of 40-60%. The wear tracks were examined with the help of a laser profilometer and the profilometric module of the tribotester CETR-UMT-2 (Bruker Corporation). The profilometric analysis results for the composite are compared to those obtained for brass. Comparing the wear tracks of the two materials, it can be found that the composite material has a better tribological behavior than the brass.

Abstract: Pneumatically actuated gripper systems are frequently used in various applications due to their multiple advantage, and particularly to their specific feature known as compliance. This is what allows manipulation of fragile objects and ensures their soft contact with the gripper jaws. The paper presents and discusses such a gripper system actuated by a pneumatic muscle. Structural, constructive and functional models of a novel gripper system are presented and its main motion characteristics highlighted.

Abstract: An overturning safety statically procedure for a road rail machine, with a dual rolling system road and rail, in railway disposition it is show in the present paper. It is analyses the load distribution of the pairs wheels of the machine.

Abstract: With responsibility as its central element, sustainable development is a concept that calls for permanently increasing information usage while minimising material and energy consumption. Waste – particularly of energy – cannot last, and is evidently not a long-term solution. In the field of machine-tools structures deemed sustainable fulfil their functions for a sufficiently long period of time, while consuming as small as possible amounts of energy and including a small as possible volume of material. In a machine-tool, as in numerous other industrial products, energy consumption in deployment significantly exceeds that of their manufacturing. A conclusive example is that of mechanical presses, machine-tools with long service lives and considerable deployment energy consumption. With increasing stiffness of presses, deployment energy consumption is smaller. Detailed research conducted by the authors has yielded a series of innovative constructive solutions for mechanical press cast C-frames – frames with ribbed lateral walls, frames with pre-stressed front columns and shortened frames – with increased stiffness and minimum additional metal consumption as their main relevant characteristics. The finite element based study of these novel constructive solutions has revealed stiffness increases of 1 to 12 %, significantly depending on the type of constructive solution. The novel solutions can be combined in view of cumulating the obtained positive effects. The paper presents relevant examples of such combined constructive solutions and the results related to stiffness increase obtained by means of the conducted FEA study.

Abstract: This study deals with the problematic of vibratory equipments driving system taking into account both the requirements of functional performances related to the final technological quality, and the dynamic phenomenon appears during the working cycle according to the transmission way from the energy source to the vibration generator. This analysis provides useful assessments for equipment design no matter the technological machine type. Hereby this study tries to dignify the dynamic state deviations induced by the components characteristics of the driven equipment, and to reveal the means for minimizing the parameters variances.