Effect of fracture tunneling in DWT Tests

Marotta, Emanuele; Minotti, Mathilde; Salvini, P

doi:10.1016/j.engfracmech.2011.09.003

Cited by 2 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The constrain effect due to thickness can be ignored far away the fracture tip, but its contribute is very remarkable close to the tip, where a tri‐axial stress distribution occurs. Moreover, by full scale burst tests of buried pipelines, an important longitudinal strain of the pipe is generated by an additional stress component in the longitudinal direction 21 . The suggested experimental layout is not able to reproduce on a SEN‐B specimen all these components of the stress; however, it represents an important improvement.…”

Section: Experimental Measurementsmentioning

confidence: 99%

“…Moreover, by full scale burst tests of buried pipelines, an important longitudinal strain of the pipe is generated by an additional stress component in the longitudinal direction . 21 The suggested experimental layout is not able to reproduce on a SEN-B specimen all these components of the stress; however, it represents an important improvement. It extends the stress distribu-tion along the ligament and expands the part of the test characterized by stable fracture-propagation.…”

Section: E X P E R I M E N T a L M E A S U R E M E N T Smentioning

confidence: 99%

“…The exhaustive description of the digital system of acquisition is given in Refs. [16,21]. Here, we discuss the whole procedure to gain the kinematical movements of the mechanical components, exploiting the identified locations of the markers, see Figs 1 and 2.…”

Section: General Description Of the Experimental Set‐upmentioning

confidence: 99%

See 2 more Smart Citations

New experimental set‐up to approach pipeline fracture behaviour by three‐point bending specimens

Minotti

Salvini

2012

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

A B S T R A C TA new experimental set-up for drop weight tear tests is proposed. Its principal characteristic is the adoption of inclined supports driving the hinges connected to the specimen. This choice accomplishes the need that the specimen was subjected to a persistent stress field in the ligament, thus approaching the stress field experienced by a crack propagating in a pipeline. This set-up requires a proper processing of the data that is accurately explained in the paper. The tests are conducted under a quasi-static loading but the method has been designed to apply in dynamic tests.Keywords Drop Weight Test; fracture propagation; pipelines. N O M E N C L A T U R Ea = horizontal offset of the hammer contact point a' = value of a taken account the specimen stiffness cut = number of frame in which the two steps are joint D (R|L) = contact points of rectilinear bar and hinges disp = vertical displacement of the rectilinear bar Drop = vertical displacement of the hammer contact point E EndCon = energy lost in the specimen connections E Flow = energy associated to longitudinal stretch E Frict = energy lost in overall frictions E Lig = energy of the bending at the ligament section E TOT = total energy put in the system F (R|L) = intersection between supports and rectilinear bar F Lig = axial load F Frict = value of friction force F Res = residual value of the friction force flow = horizontal displacement of the specimen G (R|L) = contact points of the hinges with the supports H = height of the specimen

show abstract

Section: Experimental Measurementsmentioning

confidence: 99%

Section: E X P E R I M E N T a L M E A S U R E M E N T Smentioning

confidence: 99%

See 1 more Smart Citation

New experimental set‐up to approach pipeline fracture behaviour by three‐point bending specimens

Minotti

Salvini

2012

Fatigue Fract Eng Mat Struct

Self Cite

View full text Add to dashboard Cite

show abstract

Evaluation and instrumentation of the drop weight tear test

Vervaet¹,

Waele²

2012

IJSMED

View full text Add to dashboard Cite

With the use of high strength and high toughness steels in the pipeline industry it has become necessary tobetter understand the factors which influence the reliability and integrity of oil and natural gas pipelines. TheDrop-Weight Tear Test (DWTT) is a common test method to determine the fracture appearance andfracture ductility of steel. Its fundamental purpose is to determine the appearance of propagating fracturesin steels over the temperature range where the fracture mode changes from brittle to ductile. But there arestill many subjects of discussion concerning which results must be obtained, in which manner they shouldbe obtained and how they should be interpreted. Is it still possible to deduce a shear appearance fromsamples which have such an abnormal fracture that they used to be discarded as invalid ? Could resultsfrom the DWTT be correlated with the Crack Tip Opening Angle (CTOA), which is particularly important forfinite element modelling ? What to think about methods such as the two specimen CTOA and the simplifiedsingle specimen method ? How severe is the effect of tunnelling in contemporary linepipe steels and howcan this be dealt with ? Many questions still remain and many aspects are still vague despite the correlatingecological, economical and safety issues. Therefore, there is a major necessity for further investigations.

show abstract

Effect of fracture tunneling in DWT Tests

Cited by 2 publications

References 19 publications

New experimental set‐up to approach pipeline fracture behaviour by three‐point bending specimens

New experimental set‐up to approach pipeline fracture behaviour by three‐point bending specimens

Evaluation and instrumentation of the drop weight tear test

Contact Info

Product

Resources

About