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Plastic bending of beam

Description:

The experiment hardware fits onto a Aluminum Frame. Students fix a specimen beam in chucks at both ends of a backboard. The chucks can either clamp the beam, or hold it on a knife-edge. The students then load the beam using a screw mechanism and electronic load cell. A long-travel digital deflection indicator on the backboard measures specimen deformation. To compensate for the specimen shortening as it deforms, one of the chucks moves along the backboard, relative to the deformation. Students continue to apply a load until the specimen beam is in the fully plastic condition, that is, the beam has undergone plastic collapse. They then compare the beam behaviour with theoretical predictions based on traditional yield stress theory. The lecturer guide provides details of the equipment including sample experiment results. The student guide describes how to use the equipment and gives experiment procedures.

Learning Objective:

Relationship between load and deflection for beams loaded to the plastic condition

Introduction to form factor

Introduction to limit state design

Relationship between maximum loading and plastic hinge formation for a simply supported beam, a propped cantilever and a fixed beam

Device component:

Aluminum frame

Fixed and roller support

Loadcell

Beams

Deformation of straight beam

Description:

Beams are key structural elements in mechanical engineering and in construction. A beam is a bar-shaped component in which the dimensions of the cross-section are much smaller than the length and which is subjected to load along and perpendicular to its longitudinal axis. The load perpendicular to the longitudinal axis causes a deformation of the beam – that is, bending. Based on its size, the beam is viewed as a one-dimensional model. The science of the strength of materials deals with stress and strain resulting from the application of load to a component. Many fundamental principles of the strength of materials can be illustrated well by a straight beam. The beam under investigation in this unit can be supported in different ways. This produces statically determinate and indeterminate systems which are placed under load by different weights. The load application points are movable. Three dial gauges record the resulting deformation. Three articulated supports with integral force gauges indicate the support reactions directly. The articulated supports are height-adjustable, so as to compensate for the influence of the dead-weight of the beam under investigation. A fourth support clamps the beam in place. Five beams of different thicknesses and made of different materials demonstrate the influence of the geometry and of the modulus of elasticity on the deformation of the beam under load. The various elements of the experiment are clearly laid-out and housed securely in a storage system. The complete experimental setup is arranged in the frame.

Learning Objective:

Deformation of a cantilever beam or simple supported beam for statically determinate and indeterminate condition

 Elastic line differential equation formulation

Investigate beam curve

Supports reaction force calculation

Comparison between experimental and theoretical data

Maxwell-Betti coefficients and law

Virtual work application

Device component:

Aluminum frame

Supports

Dial gauges

Specimens and weights

Steam Engine

Description:

In a steam engine thermodynamic energy in the form of vapour pressure from steam generators is converted into mechanical energy. This can be used further downstream in the process to generate electricity or to power machinery and vehicles. A steam power plant consists of a heat source for generating steam, a turbine or steam engine with generator and a cooling device for condensing. This unit contains the main components of a steam power plant. steam is generated in a gas-fired steam boiler and fed to a piston steam engine. The energy from the steam is converted into mechanical energy by a piston and a crankshaft assembly. A generator in the form of a DC motor generates electricity from the mechanical power. Four light bulbs are used as consumers of the resulting electrical energy. The exhaust steam is condensed in a water-cooled condenser. Safe operation is ensured by safety devices that monitor the boiler temperature and a safety valve. The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Experimental and practical Possibilities:

demonstration of the function of a steam engine

familiarisation with the components of a steam power plant and how they interact

recording the vapour pressure curve

effect of re-evaporation and backfeed of cold water

determining fuel consumption, the amount of steam generated, the boiler efficiency and the capacity of the condenser

Steam boiler

Steam engine

Generator

Condenser

Feed water tank