Search results for "Fracture process"
showing 3 items of 3 documents
On the Effect of Various Heat Treatments on Microstructure of AISI 4130 Steel Used in Sour Service Pipes
2020
Abstract Nowadays welding is the most common way to connect metal parts and structures. One of the challenges connected to welding it that heat output from the welding alters the microstructure of the metal creating the heat affected zone (HAZ) near the weld. In steel welds HAZ is often harder and more brittle than the base material due to formation of martensite. This might cause hydrogen induced cracking and speed up the fatigue of the weld. To mitigate the martensite formation in the HAZ different heat treatments, like preheat, interpass and PWHT are often applied. However, for 4130 steel, preheat and interpass temperatures are not expected to restrict martensite formation due to materia…
Friction of Shear-Fracture Zones
2017
A shear fracture of brittle solids under compression undergoes a substantial evolution from the initial microcracking to a fully formed powder-filled shear zone. Experiments covering the entire process are relatively easy to conduct, but they are very difficult to investigate in detail. Numerically, the large strain limit has remained a challenge. An efficient simulation model and a custom-made experimental device are employed to test to what extent a shear fracture alone is sufficient to drive material to spontaneous selflubrication. A “weak shear zone” is an important concept in geology, and a large number of explanations, specific for tectonic conditions, have been proposed. We demonstra…
Fatigue of Mooring Chains Connected to Offshore Floating Structures Considering Out of Plane Bending Effects
2019
Abstract Reliability against fatigue fracture is an issue of major concern in the design of offshore mooring systems with chain segments. The present paper describes the investigation of the effect of OPB (out of plane bending) and IPB (in plane bending) loading modes on the fatigue performance of chain links in critical positions. The hang-off design at the floater is based on long rods with bearings at the connection points to the floating structure. The purpose of the paper is to shed some light on possible design improvements on the connection design when using the available design guidelines for calculation of combined Tension-Bending fatigue in the mooring line. A challenge when using…