Department of Mechanical and Materials Engineering
The University of Western Australia

Notes on

DESIGN AND ANALYSIS

OF MACHINE ELEMENTS

 

Douglas Wright

What is Design?; why do we design ?; how do we design - problem statement, creating a bank of solution candidates, constraints & criteria, practicalising the candidates, evaluating the candidates, the feasibility study; where do we go from here?; more advanced considerations.
Appendices - an improvement problem; analysis of a spring driven vehicle; springs as energy stores; extract from JCH Roberts, Creativity.
 

Safety factor; stress concentration; static indeterminacy; elementary load building blocks; stress & strain resolution; failure theories; putting it all together; design equations for static round shafts; power transmission shafts.
Appendix - indeterminate assemblies of multiple components.
 

Castigliano's theorem; curved beams; asymmetric bending; contact stresses.
 

Types of springs; close coiled round wire helical compression springs; the spring characteristic; stresses & stiffness; buckling; wire materials; presetting; fatigue loading; spring design.
Appendix - presetting a torsion bar.
 

Thread geometry; screw thread mechanics; static failure; loads in an elastic bolted assembly; preload and its control; fluid pressurised joints; bolt fatigue; non-uniformly loaded bolt groups.
 

Fillet welded joints; geometric properties of lines; traditional analysis; throat stresses and joint safety; unified analysis; conclusion.
Appendix - the compliant lap joint.
 

Axial stress; thin cylinders; thick cylinders; design equations; strains; autofrettage; compound cylinders; torsional loading.
 

Corrosion; welded joint efficiency; thin shells of revolution - heads; compensation; pipes and flanges; inspection openings; supports; design.
 

Characteristics of a steady load and of a motor; matching a motor to a given steady load; acceleration; periodic loading. Hydraulic couplings.
Appendix - integration in practice.
 

Overall geometry; kinetics; fatigue; drive selection; effectiveness; approximate solutions; V-flat and pivoted motor drives. Traction mechanics.
Appendix - commercial selection tables.
 

System dynamics; linings. Brake analysis: translating brakes - short and long shoes; drum brakes - short, long rigid and hinged shoes; twin shoe brakes. The braked wheel; braking of vehicles; wheel lock; the vehicle and brake control characteristics.
 

Overall kinetics of a gear pair; epicyclic trains; conjugate tooth action; the involute tooth; the generation process - tooth systems; profile shift; gear meshing. Gear failure - reliability; tooth forces; bending strength; pitting resistance; varying duty.
Appendices - continued fractions; geometry of the involute gear tooth.
 

Buckling of thin walled structures; stability of equilibrium; effects of imperfections. Submerged pipelines. Practical columns - design equations.
 

Fatigue of ductiles; stress concentration; linear elastic fracture mechanics; plasticity; yielding fracture mechanics - the R6 technique; fatigue crack growth. Crack growth kinetics.
 

Linear 1-networks; extension to 2- and 3-networks. The Rayleigh-Ritz method. Finite element theory applied to elasticity - equilibrium of the discretised body; element stiffness. Implementation; condensation and bandwidth; discretisation.
Appendices - the refining process; "FEM1" User's Guide.
 

|     top      |

Edinburgh Virtual

Engineering Library