Prediction of stress relaxation from creep data in terms of average creep rate

Journal of Testing and Evaluation

Wang

Chen

2020

Self Cite

：This work aims at testing and predicting burst pressures of HDPE pipes with various groove conditions. Four types of notches including U-type, V-type, L-Type (linear type) and R-type (rectangular type) with different depth ratios are discussed. A unified damage model is proposed to predict the damage behaviors of notched HDPE pipes for different notch shapes. Results indicate that the notch shape has an

Section: Damage Model Of Hdpe Pipes With Various Notchesmentioning

confidence: 99%

Burst Pressures of High-Density Polyethylene Pipes Considering the Notch Effect: Testing and Prediction

Journal of Testing and Evaluation

Wang

Chen

2020

Self Cite

“…Especially, the creep deformation will accelerate the leakage failure of sealing systems at relatively elevated temperature. [27][28][29] Accordingly, it is necessary to study the ratcheting effect of composite materials under repeated compression taking into consideration of various important influence factors.…”

Section: And Stressmentioning

confidence: 99%

Compressive ratcheting and creep of non-asbestos fibre composite considering temperature effect

Journal of Composite Materials

Dai

et al. 2018

Self Cite

Compressive ratcheting response and creep of non-asbestos fibre composite are tested based on a designed compression–compression clamp for plate-shape specimens. The influences of temperature, stress amplitude and stress rate are discussed in detail. A two-stage constitutive model is developed to describe the compression-resilience relationship of non-asbestos fibre composite. Results present that a crescent-shaped stress–strain relationship of non-asbestos fibre composite is observed under repeated compression, and the proposed two-stage constitutive model can predict the compression-resilience curve for the first cycle very well under various temperatures and stress rates. Additionally, the ratcheting strain of non-asbestos fibre composite obviously enhances with increasing the temperature. However, it has a little change when the stress rate and stress amplitude are varied based on the experimental data. The ratcheting strain rate per cycle reduces promptly during about the first 75 cycles, and it is always less than 1 × 10−4 per cycle during the subsequent cycles and tends to shakedown. Moreover, the ratcheting strain with small stress amplitude is very close to the creep deformation at the same testing time and peak stress under different temperatures. This indicates that the ratcheting strain of non-asbestos fibre composite under fatigue loads with small stress amplitude can be evaluated equivalently by the corresponding creep deformation with high precision.

“…Lee et al developed a gasket‐integrated carbon/silicone elastomer composite bipolar plate to enhance the sealing reliability of proton exchange membrane fuel cell system. Under high‐temperature condition, creep and stress relaxation of gaskets and bolts have significant effect on the sealing joints . However, according to the best knowledge of authors, investigations on accumulated compressive deformation features of RGSWSSI are still very few, especially at elevated temperature.…”

Section: Introductionmentioning

confidence: 99%

Ratcheting effect of reinforced graphite sheet with stainless steel insert (RGSWSSI) under cyclic compression at elevated temperature

Fatigue Fract Eng Mat Struct

Dai

Chen

et al. 2018

Ratcheting and creep of reinforced graphite sheet with stainless steel insert (RGSWSSI) are tested under cyclic stress‐controlled compression by a self‐designed clamp from 500°C to 600°C. The effects of insert type, temperature, stress amplitude, stress rate, creep, and loading sequence are considered. Results present that ratcheting deformations for RGSWSSI with 316‐L stainless steel tanged and bonded insert approach to each other and show little rate dependence, while they slightly increase with the increment of stress amplitude and temperature. Moreover, obvious ratcheting effect takes place under cyclic pulsating loads with the peak stress of 32 MPa at 500°C or higher. The accumulated deformations of RGSWSSI under small stress amplitude only increase during about the first 25 cycles and then always turn to shakedown. It can also be estimated by the corresponding static creep strain in practical engineering with good accuracy at high temperature. This work provides important data and understanding of RGSWSSI under harsh fluctuating loads.