Combined Bending and Torsion Apparatus- Engineering Lab Training Systems

Features Low cost effective teaching Self-contained Bench-mounted Range of specimen materials Introduction to theories of failure Bending and torsional loading ratios variable 3 year warranty Range of Experiments To determine elastic failure of a specimen subjected to several ratios of bending and torsion simultaneously To compare the results with the established theories of failure Description Much of the design of parts in mechanical and civil engineering is complicated by there being biaxial or triaxial stresses for which some failure state has to be determined. Obvious examples are high pressure cylinders containing liquids or gases and concrete hinges for large bridge bearings. For more than a century, physicists, mathematicians and engineers have been proposing various theories of failure. Some theories have been attempts to explain observed failures while a few have tried to base a mechanism on fundamental properties of materials. It is evident that there is a considerable difference between the behavior of ductile and brittle materials. That apart, it is quite difficult to determine failure with sufficient accuracy in experiments designed to show which failure theory is most applicable. Hence, it is frequently found that codes of practice lay down what appears to be a somewhat empirical design method which experience has proved to be workable. This simple machine uses inexpensive test specimens made from round bar. The specimen is clamped at one end to the base bracket and at the other to a counterbalanced circular loading plate. This plate is graduated in 15° intervals. A special hanger enables pure bending, pure torque or combined loads to be applied depending on the position of the plate. The specimen deflection is measured by a dial gauge mounted diametrically opposite the load point. In the event of a specimen failure safety is ensured by set screws This equipment is part of a range designed to both demonstrate and experimentally confirm basic engineering principles. Great care has been given to each item so as to provide wide experimental scope without unduly complicating or compromising the design. Each piece of apparatus is self-contained and compact. Setting up time is minimal, and all measurements are made with the simplest possible instrumentation, so that the student involvement is purely with the engineering principles being taught. A complete instruction manual is provided describing the apparatus, its application, experimental procedure and typical test results.