Professor of materials in mechanical engineering, Imperial College, London,
Pages: 23 Published: Jan 1983
The existing so-called J-design curve is based on shallow-notch data (a/W ⩽ 0.1) and in many other ways is in a less-developed form than the corresponding crackopening displacement and R-6 procedures. A specific though simplified relationship between the three methods of assessment is pointed out and a modified J-estimation method is then proposed. The features of load or displacement control, shallow or deep notches, stress concentrations, and residual stresses are discussed and proposals made to encompass them within the revised procedure. The normalized J, JE/Y2σY2a is expressed as a function of an effective structural strain that depends upon notch depth. One equation is used to describe the load-controlled region of linear elastic fracture mechanics and contained yield, and another, the strain-controlled regime at or above ligament limit load.
fracture mechanics, J, -contour integral, structural design, residual stresses, strain concentration, elastic-plastic fracture
Paper ID: STP36801S