ABSTRACT The biaxial fatigue of a steel plate (JIS SM400B) having box‐welded (wrap‐around) joint was experimentally studied. Special concerns were focused on the effects load range ratio and compressive cyclic loading in lateral direction. direction crack propagation under tensile loading, which has phase difference π , changed according to ratio, R xy = Δ P x /Δ y . When less than 0.56, cracks propagated along toe weld ‐direction because principal stress σ at that location exceeded...

Multiaxial fatigue behaviour of box‐welded (wrap‐around) joints in a JIS SM400B steel (12‐mm‐thick plate) was examined using biaxial test facility. For the specimen, two stiffeners were attached to main plate by CO 2 semi‐automatic welding procedure. Residual stress measurements and finite element (FE) analyses also performed. Fatigue tests performed under both uniaxial (mainly out‐of‐phase) cyclic loads, results compared examined. It found that cracks specimens initiated at boxing‐weld toes...

Seafloor Massive Sulfides (SMS), which were formed by deposition of precipitates from hydrothermal fluids vented seafloor, is one unconventional mineral resources beneath deep seafloors in the world. The authors have proposed concept seafloor processing for development SMS, where useful minerals included SMS ores are separated on to be lifted while remaining gangue disposed appropriate ways. To apply column flotation, conventional methods processing, carried out simulating experiments...

This paper presents some experimental results which demonstrate restraint of fatigue crack growth in an Al–Mg alloy by wedge effects fine particles. Fatigue test specimens were machined from a JIS A5083P‐O plate 5 mm thickness and EDM starter notch was introduced to each specimen. Three kinds particles prepared as the materials be wedged into cracks, i.e. magnetic two alumina having different mean particle sizes 47.3 μm 15.2 μm. Particles kind suspended oil form paste, applied on specimen...

Restraint of fatigue crack propagation by wedge effect some fine particles was examined on a JIS A 5083P-O Al-Mg alloy.For test, 5 mm thick plate specimen with central EDM notch used. As the to be wedged into cracks, three kinds were prepared, namely, magnetic and two alumina which mean particle sizes 47.3μm 15.2μm. Before tests, each kind suspended in an oil, suspension spread surface covering part. Fatigue tests performed servohydraulic type tester test frequency 2 Hz load ratio R=0.First...

A paste comprising fine alumina particles was applied on surfaces of steel plate specimens and welded joint specimens, the effects restraint visual detection fatigue crack growth were experimentally investigated by performing tests with in situ observations a CCD microscope through various kinds fractographic elemental analyses using SEM (Scanning Electron Microscope) an EPMA (Electron Probe Microanalyser). As result, rate specimen drastically retarded wedge effect particles, 344% increase...

Abstract The fatigue strength of non‐load‐carrying fillet welded joints KE36(TMCP) steel was studied. Both residual stress measurements and tests were carried out, with the plate thickness, width heat input being varied. Specimens given a Post Weld Heat Treatment (PWHT) also prepared. had no effect on strength, because it hardly affected transverse stresses at weld toe. However, influenced distribution, significant difference in due to observed, especially when N ≥ 10 6 cycles. It found that...

ABSTRACT A paste comprising fine alumina particles was applied on surfaces of steel plate specimens and a welded joint specimen, the effects restraint visual detection fatigue crack growth were experimentally investigated by performing tests with in situ observations c harge oupled d evice (CCD) microscope through various kinds fractographic elemental analyses using an scanning electron (SEM) probe microanalyser (EPMA). As result, rate specimen drastically retarded wedge effect particles,...

Seafloor hydrothermal deposits, which were formed by deposition of precipitates from fluids vented seafloor, are one unconventional mineral resources beneath deep seafloors in the Exclusive Economic Zone Japan. The authors have proposed a concept for Mineral Processing Seafloor, where useful minerals separated on seafloor and then lifted while remaining gangue is disposed appropriate ways. In this paper studied new ball milling system was adapted under processing. A simulator mill grinding...

A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members has been newly proposed. By this method, the stress range at stop-hole edge is expected to be drastically reduced by load effect member. The chief advantages are that repair work can easily performed from only one side a cracked structure, and member set so adaptive as maintain automatically effectively even after structure around subjected some excessive tensile loads plastically deformed....

A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members, that was previously proposed by the author, has been examined for case reinitiated cracks. By this method, stress intensity factor range around a crack tip is expected to be reduced load effect members. The chief advantages are repair work can easily performed from only one side cracked structure, and member set so adaptive as maintain automatically effectively grows. Specifically, slope-type members...

An experimental study was made on the fatigue strength of non-load-carrying fillet welded joints performed with KE36 (TMCP) steel. Both residual stress measurement and tests were carried out specimens which plate thickness, width heat input for each pass varied as parameters. In order to examine effects directly, given PWHT (Post Weld Heat Treatment) also prepared.As a result, had no effect joints, because slight transverse stresses at weld toe. On other hand, influenced toe, causing...

The purpose of this paper is to make clear the influence yield stress on fatigue strength non-load-carrying fillet welded joints. First all, brief descriptions about relations between actual maximum considering weld residual and range are given, combined effect ratio shown. Then, using published test results, studied.In first step, whose stresses inferred reach stress, dealt with, an expression obtained. in next whole data treated. Finally, expressed as follows : Δσ=...

In this paper, the influence of plate thickness on fatigue strength non-load-carrying fillet weld joints is discussed, from viewpoint residual stress and concentration.The calculation methods stresses in cruciform T are presented, expressed functions thickness, yield strength, heat input. The calculated compared with experimental ones, good agreement with.The combined effects mean (or ratio) applied to strengthes joints, it confirmed that difference between two types joint due...

Seafloor Massive Sulfides (SMSs), which were formed by deposition of precipitates from hydrothermal fluids vented seafloor, has been expected as one unconventional mineral resources on deep seafloors in the oceans. The authors have proposed concept seafloor processing for SMS mining, where valuable minerals contained ores are separated while gangue disposed appropriate ways. To confirm applicability column flotation, is conventional methods, to processing, carried out experiments simulating...

A crack detection (CD) paint was applied to weld lines of a transverse rib welded joint specimen rolled steel for structures, and the effects on visual fatigue cracks were evaluated by performing test. Remarkable color development observed in CD when propagated along toe lines. At intervals test, surface SH (Secondary Horizontal) wave tests also carried out order confirm existence cracks, test results compared with paint.

A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members has been newly proposed. By this method, the stress range at stop-hole edge is expected to be drastically reduced by load effect member. The chief advantages are that repair work can easily performed from only one side a cracked structure and member set so adaptive as maintain automatically effectively even after around subjected some excessive tensile loads plastically deformed. Specifically,...

A simple method of repairing fatigue cracks using stop-holes reinforced with wedge members, that was previously proposed by the author, has been examined for case reinitiated cracks. By this method, stress intensity factor range around a crack tip is expected to be reduced load effect members. The chief advantages are repair work can easily performed from only one side cracked structure, and member set so adaptive as maintain automatically effectively grows. Specifically, slope-type members...

For pumping up deep ocean water, a SPAR type floating structure with steel riser pipe was installed in Sagami Bay, Japan, 2003. The pipe, which is 175 m long and 1.0 diameter, connected to the by two mooring chains. At middle height of strain gages were attached on surface so that they faced 8 directions at equal angles. authors measured not only strains but also motions wave current conditions from 2003 2005. From these results actual sea, it found (or stresses) are mostly concerned...

There are some ships of which stress states at fatigue crack initiation spots affected by cargo loading conditions. For example, a bilge knuckle part double hull tanker, the mean is tensile on full load condition while compressive in ballast.In this paper, life weldment under wave induced cyclic with change due to was studied based following test results.·Fatigue applied (nominal) minimum set zero.·Fatigue maximum applying two blocks alternately.The block 170 MPa, and other -170 MPa.The...

In this paper, the influence of plate thickness on fatigue strength non-load-carrying fillet weld joints is examined both experimentally and analytically, from view point residual stresses.In order to control longitudinal stresses (in direction line), rib-cruciform joint specimens with various width were prepared. On one hand, which heat input for each pass was varied also prepared transverse perpendicular line). Using these specimens, stress measurement tests carried out.It found that...