Applied Mechanics and Materials Vol. 895

Abstract: In tractor brakes, when the brake is applied, tension in the operating rod causes the links to turn the two actuating disc slightly, in opposite directions. The shape of the recesses in which the hardened steel balls locate is such that, as disc move relative to each other, the ball force them apart and apply pressure to the rotating discs. The automotive industry has for many years identified weight reduction as a way of improving product competitiveness and thus the ability to make profits. In present work, an attempt has been made to reduce the thickness of link and hence achieve weight reduction and cost savings. The actuator link has been analyzed for stresses. The existing link is of 6 mm thickness and is made of C – 40 steel. The existing link of 6 mm thickness along with links of 5 mm and 4 mm thickness were considered for analysis. It is found that the stresses in 5 mm thick link are well within limits with a factor of safety of 2.3. This reduction in thickness would yield a reduction in weight of link and hence would reduce the cost of link with a saving potential of Rs.14, 40000/= per year considering the fact that 6, 00,000 tractors are sold in India every year. Experimental investigation showed the zone of failure of link is in line with the high stress zone indicated by finite element analysis.

Abstract: Stainless Steels are possessing fabrication flexibility, high hardness, durability, low maintenance, high strength and resistance to heat and corrosion. This alloy steel is extensively used in various engineering applications. Some of the conventional machining techniques results in loss of original properties of stainless steel work material and makes it to behave like ordinary material within the machined surface. Machining of Stainless steels is more challenging due to its high alloying content. Problems such as application of huge coolant supply and poor chip breaking while machining, work hardening in work material, use of cutting tools with varying tool signature, results in enhanced production cost and time. Further, it is important to ensure that there is no machine tool-cutting tool vibration leading to edge chipping of cutting tool. To avoid all these problems, Abrasive water jet machining (AWJM) is used. This paper presents the machining capabilities of AWJ on Stainless Steel304. Influence of dynamic input parameters such as jet pressure, speed of traverse and abrasive flow rate on the depth of cut is investigated. An empirical model is proposed for depth of cut and an error analysis is done with measured and modeled values of depth of cut. It was found that traverse speed influences more than other parameters. SEM images indicated smooth surface at entrance and waviness at exit side. The model proposed predicts the depth of cut more or less accurately.

Abstract: Modal analysis is a method to describe the dynamic properties of structure such as natural frequency, mode shape and damping ratio. These properties are important for design and analysis of structure in dynamic condition. MATLAB is a high-performance numerical computation and visualization software package. It provides an interactive environment with hundreds of built-in functions for technical computation, graphics, and animation. In present analysis, use of MATLAB is done for finding the free vibrational characteristics of a structure made of composite material. The study involves finding the natural frequencies of structure made of Glass-epoxy, Carbon-epoxy and Graphite fiber reinforced polyamide materials. In this case Euler’s-Bernoulli beam theory is used for analytical solution and to construct MATLAB codes. The structure considered here is a beam with fixed-free condition. The results obtained from the MATLAB are accurate comparatively, the results obtained shows that the MATLAB can be further used to write programs which involve complicated iterations and cannot be done manually. The further work can be extended for writing the programs of much more complex equations in MATLAB and obtains exact solution.