Investigation of residual deformations in innovative methods of combined mandrel drilling

Investigated the influence of the nature and microgeometrical parameters influencing surface work tool, as well as the technological lubricant to remain-wide deformation of the hollow cylindrical specimen of a brass brand of LS 59-1.

Applicability of Hollow Cylindrical Specimens to Environmental Assisted Fatigue Tests

When an environmental assisted fatigue (EAF) test is performed, the surface of a specimen has to contact with simulated LWR water. Autoclave equipment with a solid specimen is a commonly used method for EAF testing. It, however, takes time to setup a specimen into the autoclave and also it is necessary to strive to directly measure the displacement of the specimen. Another EAF testing method, which has been utilized by several research institutes, is to use a hollow cylindrical specimen. The hollow cylindrical specimen does not need the autoclave equipment and can be easily assembled to the fatigue test facility. This paper introduces the EAF test using the hollow cylindrical specimen, comparison between fatigue lives by hollow cylindrical specimens and solid specimens and gives some technical notes to use the hollow cylindrical specimen.

Elastic-Plastic Analysis for Cracked Members

Elastic-plastic finite element analyses are performed for cracked specimens of various geometries and material properties. The calculations are based on the small strain, J2-deformation theory of plasticity; employing a power hardening model for the material behavior under uniaxial tensile loading. The finite element procedure includes the use of a specialized plastic, crack tip singularity element; and, it is applicable to the geometric idealizations of plane stress, plane strain, and axial symmetry. Results are presented for tensile and bending specimens containing exterior cracks and for a hollow cylindrical specimen with a circumferential crack subjected to tensile and pressure loading. Numerical values are reported for the plastic intensity factor, the crack face separation at the exterior surface, and the J-integral. Both the implications of these results to fracture prediction and the limitations on their applicability as a consequence of geometric and material modeling idealizations are discussed.