Optimization of Plasma Cutting Parameters on Dimensional Accuracy and Machining Time for Low Carbon Steel

This work aims to study the influence of plasma arc cutting parameters on dimensional accuracy and machining time for mild steel (1010) material with the thickness (4 mm). Selected three cutting parameters (arc current, cutting speed, and arc distance) or the experimental work. 12 tests have been performed at each test one parameter has been changed with four various levels and other parameters are constant. The influence of the cutting parameters on response results (dimensional accuracy and machining time) have been studied and analyzed by using response surface methodology (RSM) using the second-order model and main effect plot have been generated of each parameter on response results by using ANOVA depended on results of response surface analysis. The results of the response surface analysis showed that the important influencing parameters on dimensional accuracy were cutting speed and arc current as well as on deviation of dimensional accuracy, and the machining time is further affected with the current more than the cutting speed and the standoff distance. The outcomes of response surface analysis showed that the optimal setting of the cutting parameters to obtain at high dimensional accuracy were (arc current= 110 A, cutting speed = 4000 m/min, arc distance = 2mm) and to obtain on less machining time was (arc current= 110 A, cutting speed = 4000 m/min, arc distance = 5mm).

Experimental Assessment of Performance of XCC Pile in Sand

XCC (X-Section Cast in place Concrete) pile is new type of pile developed on the basis of cast-in-place pile from the conventional circular pile and capable of resisting displacement. In this study, an attempt is made to investigate the performance of XCC Pile under different loading conditions viz., vertical loading, lateral loading and uplift loading. Experimental investigation is carried out on small scale model piles embedded in sand, by changing type of loading and distance between arc to diameter ratio of the pile. The relative density of soil, type of soil and spacing between the piles are kept constant during investigations. Ultimate capacities of piles are compared with those of conventional circular pile with same diameter and length. The results show that XCC pile with arc distance to diameter ratio equal to 0.3 provides higher vertical and lateral capacity to the extent of 45 % and 39 % respectively compared to that of conventional pile. XCC Pile with arc distance to diameter ratio equal to 0.4 provides higher uplift load capacity to the extent 29 % compared to conventional circular pile.

An extension to the spherical metric using polar linear interpolation

The spherical metric d_r operates on the surface of a sphere with radius r centered at the origin in a linear space R^n. Thus, for any pair of points (p,q) on the surface of this sphere, (p,q) is in the domain of d_r and d_r(p,q) is the "distance" between those points. However, if x and y are both in R^n but are not on the surface of a common sphere centered at the origin, then (p,q) is not in the domain of d_r and d_r(p,q) is simply undefined. In certain applications, however, it would be useful to have an extension d of d_r to the entire space R^n (rather than just on a surface in R^n). Real world applications for such an extended metric include calculations involving near earth objects, and for certain distance spaces useful in symbolic sequence processing. This paper introduces an extension to the spherical metric using a polar form of linear interpolation. The extension is herein called the "Lagrange arc distance". It has as its domain the entire space R^n, is homogeneous, and is continuous everywhere in R^n except at the origin. However the extension does come at a cost: The Lagrange arc distance d(p,q), as its name suggests, is a distance function rather than a metric. In particular, the triangle inequality does not in general hold. Moreover, it is not translation invariant, does not induce a norm, and balls in the distance space (R^n,d) are not convex. On the other hand, empirical evidence suggests that the Lagrange arc distance results in structure similar to that of the Euclidean metric in that balls in R^2 and R^3 generated by the two functions are in some regions of R^n very similar in form.