stress and residual stress are the main problems in the operating performance of materials. they are the principal causes of material failure and can affect life time of component. however measurement or predictions of them are typically difficult. two common non-destructive methods, x-ray diffraction and ultrasound are not reliable methods for subsurface residual stress measurements and destru...

in this research, a novel method to decrease micro-residual stresses of fibrous composites by adding carbon nanotubes (cnts) is proposed in detail. the negative coefficient of thermal expansion and the high young’s modulus of cnts can be utilized to counterbalance the process induced residual stresses in composites. to this end, first, the effects of adding cnts to the matrix of fibrous composi...

structural health monitoring of cracked structures is one of beloved subject of researchers recently. consider of crack behavior in the water and energy pipeline is important because of environmental problems. in this paper consider of crack parameters in the underwater pipe subjected to mechanical transient load is investigated. for this purpose, three- dimensional parametric model of cracked ...

In order to achieve integrated condition in the girth welding of high pressure natural gas transmission pipelines, the weld zones and its surrounding area should have good mechanical properties. Residual stresses are an important defect especially in the girth welding of the pipeline. In this study, two API X70 steel pipes (with spiral seam weld) of 56 inches outside diameter and 0.780 inch wal...

shrink fit process is a useful technique in order to introduce beneficial residual stress in compound pressure vessels. in this paper, the effects of geometrical tolerances on residual stresses have been studied for a compound shrink fitted pressure vessel, practically. three layers, which are designed based on an optimum nominal thickness and overlap dimensions and tolerances, have been fitted...

all the producing and assembling processes exert residual stress on the pieces that may lead to structural failure. therefore, calculating the residual stress in such structures has been common in recent years. in this article, distribution of temperature and residual stress resulting from arc welding in three-pass butt joint in p91 austenitic stainless steel pipes is calculated and estimated u...

Due to the complex geometry and thermos-mechanical loading, cylinder heads are the most challenging parts among all parts engines. They must endure cyclic thermal and mechanical loading throughout their lifetime. Cast aluminum alloys are normally quenched after solution treatment process to improve aging responses. Rapid quenching can lead to high residual stress. Residual stress is one of the ...

 One of the surface defects that arise in sheet metal working is when the part removes from the die. Since there are no external forces to make this defect, the origin of such fail is known as residual stress. Residual stress can develop in sheet metal forming due to non uniform deformation. In this paper, the workpiece is carbon steel with different volume fractions and arrangement of ferrite ...

this research investigates the effect of the post-cure time on the residual stresses in laminated composites. laminated composites were made of t300 carbon fibers and epoxy resin. the post-cure process was carried out at the constant temperature of 120 °c for 6 and 12 hours for two specimens. the slitting method was employed to determine through-thickness residual stress distribution of the com...