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stress relaxation testing

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Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006941
EISBN: 978-1-62708-395-9
... of constant strain is the basis of typical stress relaxation testing, in which the relaxation modulus function can be empirically measured by testing a plastic at constant temperature, measuring the force with respect to time to maintain constant strain and fitting the data to the relaxation modulus given...
Series: ASM Handbook
Volume: 11A
Publisher: ASM International
Published: 30 August 2021
DOI: 10.31399/asm.hb.v11A.a0006807
EISBN: 978-1-62708-329-4
... creep testing and remaining-life assessment, and pressure vessel time-dependent stress analysis showing the effect of stress relaxation at hot spots. creep curve creep testing elevated-temperature life assessment heater tubes high-temperature components hydrogen attacks remaining-life...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006930
EISBN: 978-1-62708-395-9
... logarithmically. When stress relaxation is being performed, it is common to plot the modulus, G, versus time, and with creep testing, to plot the compliance, J, as a function of time. There are elongational counterparts to the shear parameters shown in Table 1 , although they are not shown in the table. Molten...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.auto.c0090433
EISBN: 978-1-62708-218-1
... produced a greater predisposition for stress relaxation. Additives Chemical composition Clips Injection moldings Molding resins Stress relaxation Thermal analysis Wire clips Nylon 6/6 (Other, general, or unspecified) processing-related failures A production lot of plastic wire clips...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006932
EISBN: 978-1-62708-395-9
... proposed a method of estimating the average internal stress in a cross section of metal by stress relaxation ( Ref 16 ). In stress relaxation tests, strain is kept constant, and stress decay is monitored as a function of time. Other researchers suggested a method of analyzing stress relaxation data...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.petrol.c9001590
EISBN: 978-1-62708-228-0
.... Welded structures are particularly susceptible because of the potential for high residual stresses (up to the yield strength of the base material) that may result if the weld has not been post weld heat-treated. Test material taken from components that have failed by stress relaxation cracking will still...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001760
EISBN: 978-1-62708-241-9
... lengths during the test were measured by ultrasonic device. Stress relaxations were calculated and are shown in Table 1 . The results show that after the running-in test, the bolt lengths increase and then decrease because of stress relaxation. The changes in lengths were symmetric. Stress relaxation...
Series: ASM Handbook Archive
Volume: 11
Publisher: ASM International
Published: 01 January 2002
DOI: 10.31399/asm.hb.v11.a0003528
EISBN: 978-1-62708-180-1
... 25 ) is usually applied. In the case of four-point bend testing, a strain gage is attached to the opposite side and/or near the measurement location on the specimen. The applied strains are recorded via a strain gage, and the stresses are measured by XRD at different load increments. The maximum...
Series: ASM Handbook
Volume: 11
Publisher: ASM International
Published: 15 January 2021
DOI: 10.31399/asm.hb.v11.a0006768
EISBN: 978-1-62708-295-2
... to proceeding with residual-stress measurements. Collection Time Low collection times can introduce random errors due to insufficient x-ray counting statistics ( Ref 1 , 7 , 36 ). Random errors become apparent during repeatability tests; therefore, x-ray data-collection times should be increased...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001814
EISBN: 978-1-62708-241-9
..., setting off the fire. The failure mechanisms include stress relaxation cracking of a large diameter Incoloy 825 tube, stress rupture of a 4.65 in. thick chromium steel shell wall, and the oxidation of chromium steel exposed to hot syngas. The gasifier process and operating conditions that contributed...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006921
EISBN: 978-1-62708-395-9
..., electrical resistivity, vapor permeability, and reduction in pre-stress (stress relaxation). There are a few ways this has been attempted. Chemical Degradation and Aging Testing Oven aging tests and chemical exposure tests have been performed on plastic materials since the beginning of their use. Oven...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.power.c0048850
EISBN: 978-1-62708-229-7
..., with associated creep relaxation. Boilers Electric power generation Steam lines Thermal stresses 316 UNS S31600 Thermal fatigue fracture Visual inspection of a type 316 stainless steel main steam line of a major utility boiler system revealed cracks on its outer surface near a hanger lug...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006929
EISBN: 978-1-62708-395-9
... materials and resins. It explains how absorbed moisture affects a wide range of properties, including glass transition temperature, flexural and shear modulus,creep, stress relaxation, swelling, tensile and yield strength, and fatigue cracking. It provides relevant data on common polymers, resins, and fiber...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.modes.c9001487
EISBN: 978-1-62708-234-1
..., a certain measure of creep and stress relaxation takes place. Under a slow rate of loading, the occurrence of creep will result in an increase in the amount of plastic strain, while at temperature, relaxation will cause the stress to decrease with time due to plastic flow of the copper. As a consequence...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006934
EISBN: 978-1-62708-395-9
... Abstract This article describes the general aspects of creep, stress relaxation, and yielding for homogeneous polymers. It then presents creep failure mechanisms in polymers. The article discusses extrapolative methods for the prediction of long-term creep failure in polymer materials...
Series: ASM Failure Analysis Case Histories
Publisher: ASM International
Published: 01 June 2019
DOI: 10.31399/asm.fach.modes.c0092131
EISBN: 978-1-62708-234-1
... spring and an outer spring (both of patented and drawn high-carbon steel wire) taken from another cylinder in the same engine were examined in the laboratory to determine why one had distorted and the other had not. Investigation (visual inspection, microstructure examination, and hardness testing...
Series: ASM Handbook
Volume: 11B
Publisher: ASM International
Published: 15 May 2022
DOI: 10.31399/asm.hb.v11B.a0006917
EISBN: 978-1-62708-395-9
... the circumstances surrounding the failure, a fractographic evaluation to assess the cracking, and analytical testing to evaluate the material, design, manufacturing, and environmental factors. environmental stress cracking fractographic evaluation plastics MANY FRACTURE MECHANISMS exist that can lead...
Series: ASM Failure Analysis Case Histories
Volume: 3
Publisher: ASM International
Published: 01 December 2019
DOI: 10.31399/asm.fach.v03.c9001852
EISBN: 978-1-62708-241-9
... and stress-life curves, and Coffin-Manson parameters have also been acquired. Fractography of the fractures/failed test sample’s surfaces, examination of the microstructure of the electroformed nickel tool, and micro hardness test across the surface and through the thickness have been carried out to identify...
Series: ASM Failure Analysis Case Histories
Volume: 2
Publisher: ASM International
Published: 01 December 1993
DOI: 10.31399/asm.fach.v02.c9001306
EISBN: 978-1-62708-215-0
... around the circumference. The wheel studs are a classic example of fatigue in rotational bending at high nominal stress with mild stress concentration. Fig. 2 Fracture surfaces of wheel stud shown in Fig. 1 . The shank end of the stud was not removed from then nut. Both surfaces were slightly...
Series: ASM Failure Analysis Case Histories
Volume: 1
Publisher: ASM International
Published: 01 December 1992
DOI: 10.31399/asm.fach.v01.c9001119
EISBN: 978-1-62708-214-3
... a tensile strength ranging from 1790 to 1950 MPa (260 to 283 ksi) for the material drawn to a 4.9 mm (0.192 in.) diam wire size. No tests were conducted. Stress Analysis Analytical Preliminary coil stress calculations were performed to provide an order-of-magnitude assessment of the operating...