Strength of Material Lab
Introduction: Properties of the materials are very important in the process of designing the durable components / machines / structures etc. These properties include mechanical properties, thermal properties, electrical properties, optical properties or magnetic properties or deterioration properties. Mechanical engineers are mainly concerned with the mechanical properties like strength, ductility, hardness, brittleness, toughness, creep, fatigue strength of the materials. These properties play an important role for the structures and components that are intended to sustain various type of loads under the given service conditions. Different applications need specific mechanical properties. Sometimes hardness is required at the surface of the components, like gears, to make them wear resistant and sometimes toughness is required to resist impact loading. One of the principle concerns ofan engineer is the analysis of materialsused in structural applications. The termstructure refers to any design that utilizes materials that support loads and keeps deformation within acceptable limits. Designing machines, structures, and vehicles, which are reliable as well assafe and cost effective, requires a proper knowledge of engineering as well as material selection.
Elementary strength of materials is the physical science that looks at the reaction of a body to movement and deformation due to mechanical, thermal, or other loads. The basis of virtually all mechanical design liesin how the material reacts to outside forces. Mechanics is the core of engineering analysis and is one of the oldest of the physical sciences. The basis of structural design is simply todesign a component where the stress does not exceed the strength of the material, causing failure.
Material failures may be time dependant such as creep or fatigue failure due to cyclical loading, or failures may be time independent where static loading causes rapid fracturing ofthe material. Some members rely on deformations to function, such as a spring, but an excessive amount causing permanent changes is typically avoided. Materials capable of sustaining large amounts of plastic deformation are said to behave in a ductile manner, those that fracture without much plastic deformation are said to behave in a brittle manner. In this laboratory, students will have the opportunity to applyloads to various materials under different equilibriumconditions.
This laboratory provides the know-how of the mechanical properties of the materials through various experiments on testing machines and equipments. Mainly destructive testing is used to determine different mechanical properties of the given specimen. The student will performtests on materials in tension, torsion, bending, and buckling. These conditions and/or constraints are designed to reinforce classroomtheory by having the student performrequired tests, analyze subsequent data, and present the resultsin a professionally prepared report.
Various equipments present in Strength of Materials lab:
Name of the Article
Universal Testing Machine
Electronic microprocessor based digital indicator, Capacity 40 Tonnes, least count (Resolution) 4kgf on the entire rated capacity of the machine,
Accessories: 1. Clamping jaws for testing round and flat test specimens under tension tests, 2. A pair of compression platens, duly hardened, ground and polished, with the bottom platen provided with guide-lines for placing the test specimen co-axial with the hydraulic RAM, 3. Load cell extensometer with ring for calibration complete, 4. A table with adjustable rollers complete with mandrel for conducting bending/transverse tests. 5. Double shear test block and bush, 6. Load stabilizer.
Impact Testing Machine
Capacity 30 kgm(300jules), least count 0.2Kgm, complete with strikers for conducting IZOD and CHARPY TESTS.
Fatigue testing Machine
Complete with jigs and fixtures mounted an elegant table with motor, weights, electronic digital revolution counter.
Torsion testing Machine
Capacity 200 kgf, (Mechanical)
Spring Testing Machine
Capacity 2000 kfg, Contraption for holding tension spring and a pair of compression platens for holding compression.(Hand cum electrically operated)
Vickers Hardness Tester: Capacity 50 kgf, Vickers microscope, Vickers conversion table, Vickers pyramid indentor.
Rockwell Hardness Tester: Capacity 150 Kgf, Ball and Diamond indentor, Test blocks, Scales (A, B and C).
Brinell Hardness Tester: Capacity 3000 Kgf, Balls of 5mm and 10mm diameter, Test blocks, Ball holder, Brinell Microscope with illuminating arrangement and BHN conversion Table.