The STRENGTH of MATERIALS range enables clear and comprehensive learning of Materials and their Properties covering a variety of theories and topics. An understanding of the way in which materials act and react, is fundamental when studying the application of loads on a variety of fixed or moving structures. The STRENGTH of MATERIALS form a comprehensive range of equipment, from fixed beams through to rotating machines apparatus, equally suitable for demonstration and experimental work.
All the STRENGTH of MATERIALS hardware operates in a standalone mode, with a large number being supplied with Data Acquisition Interfaces and Software.
The object of this experiment is to determine what levels of combined bending and torsion cause elastic failure in different materials, and to compare them with various theories of failure. The apparatus uses specially machined ‘necked’ specimens which are clamped at one end to the base plate and at the other end to a counterbalanced circular loading plate.
A piece of material in compression is called a strut. If it is short and stubby it will fail by compressive stress, but if it is slender the failure mode is that of buckling. The load at which the strut buckles depends on the way in which the ends are restrained. Built-in ends resist buckling more than ends which are free to move. The apparatus shows how the buckling mechanism occurs, and the influence of the end restraint.
Spiral springs are used to provide a resisting or restoring torque to a shaft when it is rotated through an angular displacement. They exhibit similar stiffness characteristics to linear springs, except that the effect is one of torque rather than force. The stiffness of a spiral spring depends on its physical dimensions and the rigidity of the steel strip from which it is formed.
The apparatus has been designed to illustrate the basic features of electrical resistance strain gauges and their application in measuring bending and torsion. A cantilever has a single gauge bonded onto its surface, and an identical gauge is fixed to an unstressed piece of the same material for temperature compensation.
This apparatus has been designed to introduce students to the effects of fatigue. A motor rotates a specimen through a gear and pulley arrangement which can be adjusted. During the rotation the specimen is subject to sinusoidal variation of bending stress.