Motion Analysis of Torsional Testing Machine to Reduce Impact Load Using SOLIDWORK

Mechanical testing is a standard and essential part of any design and manufacturing process, for ensuring safe working of mechanical component and for ensuring a cost-effective design. Torsion Testing Machine is designed for conducting Torsion and Twist on various metal wires, tubes, sheet materials, torque measurement, in this torque can be applied to testing specimen by geared motor through gear box. But the main difficulty with analytical torsion testing machine is that after test is complete and specimen breaks the trolley on which the test specimen is clamped it can impacted heavily to the rubber stopper mounted on the guide ways of the machine which distort the machine assembly. In this study motion study is done, using SOLIDWORK software by introducing spring at the place of stopper and try to minimise this impact load of the trolley on the machine. Keywords: Torsion testing, Motion analysis, impact load, spring design, SOLIDWORK software

Double twist torsion testing to determine the non recrystallization temperature

A double-twist torsion testing technique has been developed using a 316 stainless steel as an exemplar material to experimentally assess recrystallization behavior and determine the non-recrystallization temperature (Tnr). This new method was compared to the traditional methods of double-hit compression and multi-step hot torsion testing. The double-twist torsion test allows Tnr to be related to the extent of austenite recrystallization through measurements of fractional softening while accommodating multiple deformation and recrystallization steps with a single specimen. The double-twist torsion test resulted in average Tnr values similar to those determined with multi-step hot torsion, and a partially recrystallized microstructure was observed in the vicinity of the calculated Tnr for all three methods. The ability of the double-twist torsion test to relate the experimental Tnr to the evolution of austenite recrystallization via fractional softening measurements while incorporating effects of multiple deformation steps offers an advantage over traditional methods for quantifying changes in austenite recrystallization during thermomechanical processing.

Method for Evaluating Potential Maximum Shear Strain for a Fine Metal Wire in Torsion Testing

The torsion number of drawn fine high carbon steel wires was measured through torsion testing. The angles between the scratches on the tested wire surface and its longitudinal axis were measured. The shear strain calculated from torsion number γt, shear strain at fractured point γf, and plastic shear strain γpc were evaluated. The following results were obtained. First, the shear strain distribution homogenized; further, torsion number per unit length N, γt, and γpc increased when decreasing the difference between γf and γpc where γpc subtracted from γf (=Δγfpc) > 0. Second, the external factors caused non-uniform shear strain distribution and reduction from the potential maximum shear strain, even for the wire that was hardly affected by the internal factors. The difference of shear strain non-uniformity caused a variation in reduction from the potential maximum shear strain. The internal factors included non-uniform microstructure and existence of inclusions and voids. The external factors were caused by the testing machine and setting of the sample. The potential maximum shear strain was obtained when the effects of internal and external factors were inhibited. Finally, two evaluation methods of the potential maximum shear strain were suggested. One method identifies a sample with a small Δγfpc, and a large γpc where Δγfpc > 0. This sample can be regarded as having the closest strain to the potential maximum shear strain. The other method determines γpc when Δγfpc is closest to 0. This value can be interpreted as plastic strain of the potential maximum shear strain.

Combined bending–torsion testing device for characterization of shape memory alloy endodontic files

Design has an important influence on mechanical response of endodontic instruments made of shape memory alloys. The experimental and numerical prediction of their thermomechanical response is necessary to improve their behavior during operating inside root canal. Due to the curved and tapered shape of the dental canal, endodontic files are subjected to rotating bending during the root canal preparation phase. These rotative bending could ever be combined with torsion when the instruments are engined in the root canal. Bending and torsion tests available in the standard ISO 3630-1 do not take into account this combined loading leading to a response different from the one obtained by superposition of separated bending and torsion loadings. This article details the design and the realization of bending–torsion testing device particularly adapted to shape memory alloy endodontic files. It allows to control the torsion and the bending rotations in a separate or a combined way. Qualification tests using this bending–torsion testing device on NiTi wires showed a good agreement between the experimental and the simulated responses. Finally, this bending–torsion testing device allowed to analyze the response of various NiTi endodontic files, currently used in endodontics, subjected to bending, torsion, and combined bending–torsion loadings. Obtained results showed clearly that combined bending–torsion loading changes significantly the shape memory alloy file response.

The Ways of Reaching the Specified Mode of Testing Samples for Torsion with Variable Strain Rate

The paper is devoted to the practical implementation of the new torsion testing method for studying rheological properties of materials in a hot state. This method involves the testing of cylindrical samples in the grips of a test setup, the angular velocity of which changes exponentially. The testing mode allows you to restore the hardening curves of a material according to the test results. This article aims to formulate the requirements for possible ways to implement the proposed testing method, and presents two different ways to obtain the specified exponential testing mode. The experience of their use on the test setup in the Ural Federal University indicates the feasibility of the new testing method, as well as the possibility of a smooth transition to the specified testing mode.

Hot Strip Mill Processing Simulations on a Ti-Mo Microalloyed Steel Using Hot Torsion Testing

Precipitation strengthened, fully ferritic microstructures in low-carbon, microalloyed steels are used in applications requiring enhanced stretch-flange formability. This work assesses the influence of thermomechanical processing on the evolution of austenite and the associated final ferritic microstructures. Hot strip mill processing simulations were performed on a low-carbon, titanium-molybdenum microalloyed steel using hot torsion testing to investigate the effects of extensive differences in austenite strain accumulation on austenite morphology and microstructural development after isothermal transformation. The gradient of imposed shear strain with respect to radial position inherent to torsion testing was utilized to explore the influence of strain on microstructural development for a given simulation, and a tangential cross-section technique was employed to quantify the amount of shear strain that accumulated within the austenite during testing. Greater austenite shear strain accumulation resulted in greater refinement of both the prior austenite and polygonal ferrite grain sizes. Further, polygonal ferrite grain diameter distributions were narrowed, and the presence of hard, secondary phase constituents was minimized, with greater amounts of austenite strain accumulation. The results indicate that extensive austenite strain accumulation before decomposition is required to achieve desirable, ferritic microstructures.