How Structures Fail Dr Roger P. West Department of Civil, Structural and Environmental Engineering Trinity College Dublin 1E9 Mangonel Design

Failure Modes – Axial members Tension in a cable Tension in a cable Axial stress Axial stress Extension leading to strain Extension leading to strain Buckling in compression Buckling in compression Elastic Elastic Plastic Plastic

Failure Modes-Beams Bending of a beam Bending of a beam Depth vs width Depth vs width Tension and compression Tension and compression Bending stress Bending stress Elastic and plastic Elastic and plastic Brittle and ductile Brittle and ductile Shear in a beam Shear in a beam Bolt failure Bolt failure Plate failure Plate failure

Failure Modes Torsion Torsion Beam Beam Shaft Shaft Plastic torsion Plastic torsion Lateral torsional buckling Lateral torsional buckling

Failure Modes Other modes Other modes Cyclic - Fatigue Cyclic - Fatigue Impact Impact Corrosion Corrosion Shrinkage movement Shrinkage movement Thermal movement Thermal movement Appearance Appearance