Drop-Weight NDT Temperature Test Results for Five Heats of ASTM A517 Steel

2009 ◽  
pp. 87-87-21
Author(s):  
CE Hartbower
Keyword(s):  
Test Results ◽  
Drop Weight ◽  
Temperature Test

Instrumented drop-weight test results for normalised and tempered 9Cr1Mo steel

1996 ◽  
Vol 69 (3) ◽  
pp. 253-261 ◽  
Author(s):  
A. Moitra ◽  
P.R. Sreenivasan ◽  
S.K. Ray ◽  
S.L. Mannan
Keyword(s):  
Test Results ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test

Analysis of the Fire-Resistance of Suspen Dome Structure

2012 ◽  
Vol 166-169 ◽  
pp. 1040-1044 ◽  
Author(s):  
Zhong Ling Zong ◽  
Yong Fu He ◽  
Shi Ge Li
Keyword(s):  
Mechanical Properties ◽  
Work Performance ◽  
Test Results ◽  
Analysis Method ◽  
Steel Cable ◽  
Mechanics Model ◽  
Time Integral ◽  
Integral Effect ◽  
Dome Structure ◽  
Temperature Test

Based on the mechanical properties of steel cable under the high temperature test results, the mechanical properties, such as yield strength, modulus of elasticity of steel cable and its mechanics model were obtained. Nonlinear numerical analysis method was established based on the time integral effect. Through the analysis of the suspen-dome structure, this paper discusses the characteristics of temperature field distribution, displacement and stress. The results show that: suspen-dome structure has better spatial work performance; the weak area of the structure is at the central, the main reason of large deformation is the reduction of stiffness and strength.

Understanding Inverse Fracture: A Comparison of Results of Drop Weight Tear Tests and Partial Gas Tests

2018 ◽  
Author(s):  
Marion Erdelen-Peppler ◽  
Christoph Kalwa ◽  
Alexander Völling
Keyword(s):  
Crack Initiation ◽  
Large Deflection ◽  
Good Representation ◽  
Test Results ◽  
Fracture Test ◽  
Drop Weight ◽  
Transitional Behavior ◽  
Adverse Influence ◽  
Shear Area ◽  
High Degree

For a safe operation of gas pipelines, the prevention of propagating brittle facture is one of the most important requirements. To evaluate the transition temperature of a propagating fracture, the Drop Weight Tear (DWT) Test was developed in the 60s. Fracture surfaces of DWT specimens have been shown to correspond well to the fracture surface of a pipe exposed to a propagating fracture at a certain temperature. Historically, there have always been observations of the fracture initiating in a ductile manner in the DWT test. Nevertheless, the most widely used test standard rules out such behavior, known as inverse or abnormal fracture. As an option to prevent ductile initiation, an alternative notch is proposed. While this might have served in the earlier days, high toughness steels of today are known to provide a high resistance against crack initiation and are therefore prone to inverse fracture, even when making use of the suggested alternative notch. Other, non-standard notch types have been investigated and discussed in literature, amongst these the static pre-crack and brittle weld notch. Observations of the DWT test, especially comparing material showing non-inverse and inverse behaviour, show delayed crack initiation resulting in large deflection when the specimens are inverse. This high degree of pre-deformation of the material will have an adverse influence on the material performance by the time the crack propagates into it. This implies that the appearance of inverse fracture is a test effect in the laboratory test, and not an inherent material property, leading to the question if such DWT test results still correspond to the behavior of pipes. If the correlation is shown to be valid, the brittle initiation requirement as such becomes questionable. This study summarises investigations of different notch types in DWT tests. West Jefferson tests that have been conducted to verify the correlation to shear area fraction in DWT tests. The investigation revealed that ductile initiation could not be reliably suppressed. While neither Chevron nor static pre-crack specimen lead to any reduction of the occurrence of inverse fracture, test series of brittle weld specimens did have a higher number of valid specimens. Interestingly, the results of valid, non-inverse specimens and invalid, inverse specimens showed no shift in transitional behavior. Correspondingly, both valid and invalid specimens showed a good representation of the pipe behaviour in the upper transition region.

scholarly journals Poliomyelitis surveillance in England and Wales, 1969–1975

1978 ◽  
Vol 80 (1) ◽  
pp. 155-167 ◽  
Author(s):  
J. W. G. Smith ◽  
P. J. Wherry
Keyword(s):  
Reproductive Capacity ◽  
Paralytic Poliomyelitis ◽  
Test Results ◽  
Wild Type ◽  
England And Wales ◽  
Marker Test ◽  
Type 3 ◽  
Temperature Test

SUMMARYPoliomyelitis continued to be a rare disease in England and Wales in the period 1969–75. Only 31 paralytic and 44 cases of possible non-paralytic poliomyelitis were recorded during the 7 years.Of the 31 paralytic cases approximately one third were vaccine-associated; 3 were patients who had recently received oral poliovaccine and 7 had been in contact with a vaccinated person. Five of these 7 patients were parents of recently vaccinated children. The rate of vaccine-associated poliomyelitis was estimated in recipients to be 0·2 and in contacts 0·4 per million doses of vaccine given.Marker test results were reported on 555 strains of poliomyelitis virus isolated during 1969–75, using the reproductive capacity temperature test. Forty-eight (8·6%) resembled wild virus in this property, 15 strains being type 1, 8 type 2 and 25 type 3. Most of these isolations of apparently wild virus were from excreters with no symptoms of poliomyelitis, although 3 of the 15 type 1 strains were from patients with paralytic poliomyelitis and 3 from possible cases of non-paralytic poliomyelitis. None of the 8 apparently wild type 2 viruses was from a case of paralytic illness and only 1 of the 39 type 3 strains.Eleven of the 31 paralytic cases were in patients in whom the infection was likely to have been acquired abroad.

Effects of Crack Starter Bead Preparation in Drop-Weight Test on Nil-Ductility Transition Temperature

1999 ◽  
Vol 121 (2) ◽  
pp. 196-202
Author(s):  
M. Higuchi ◽  
T. Yamauchi ◽  
Y. Tanaka ◽  
K. Iida
Keyword(s):  
Alloy Steel ◽  
Test Results ◽  
Base Metals ◽  
Low Alloy Steel ◽  
High Toughness ◽  
Drop Weight ◽  
Steel Base ◽  
Weight Test ◽  
Drop Weight Test ◽  
Bead Height

The procedure for making crack starter weld deposit on drop-weight test (DWT) specimens was altered from two passes to one pass in about 1990. The effects of some parameters of crack starter weld process on drop-weight test results were studied. Results of this study indicated that length of overlap of the second pass and height of crack starter beads were most effective on nil-ductility temperature (TNDT). When overlap length and bead height of two-pass deposit were small enough, TNDT obtained by two-pass deposit became lower than one-pass TNDT, the discrepancy being by as much as 25°C. TNDT values for 24 Japanese steels were determined using two different DWT methods, one-pass deposit and two-pass deposit having small overlap length and bead height. The difference of TNDT depending on DWT method could be seen only for high-toughness low-alloy steel base metals. For other materials (i.e., low-to-medium-toughness low-alloy steel base metals, weld metals, and high-toughness carbon steels), TNDTS by two-pass and one-pass deposits were essentially the same. For lower-toughness steels, TNDT was frequently lower than the temperature of vTcv − 33°C), and thus, the reference nil-ductility temperature RTNDT was determined from Charpy impact test results. These results can be taken as a way of interpreting the past toughness evaluations made for operating plants using the two-pass TNDT.

Research on Resistance to Moisture Damage of Warm Mix Rubber Asphalt Mixture

2015 ◽  
Vol 744-746 ◽  
pp. 1209-1212 ◽  
Author(s):  
Guo Liang Yang ◽  
Fan Bing Meng ◽  
Li Pu Huang ◽  
Shi Jie Wu ◽  
Wei Peng Chen ◽  
...  
Keyword(s):  
Immersion Time ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Strength Test ◽  
Test Results ◽  
Splitting Strength ◽  
Order Polynomial ◽  
Best Fitting ◽  
Moisture Stability ◽  
Temperature Test

To verify the resistance to moisture damage of warm mix rubber asphalt mixture, the splitting strength test of warm mix rubber asphalt mixture (WMRAC-13) was conducted under different immersion time and immersion temperature. Test results show that freeze-thaw splitting strength of warm mix rubber asphalt mixture meets the requirement of moisture stability. The immersion splitting strengths in 60°C and 4°C decline with the extension of immersion time. The immersion splitting strengths in 60°C decline faster than those in 4°C. The best fitting function of immersion splitting strengths with immersion time obeys second-order polynomial and power function respectively, and their correlations are the best. The inflection point of attenuation curves is 3th day and 20th day respectively.

Sign in / Sign up

Export Citation Format

Share Document