Hongtao Liu¹, Maoxian Xiong¹, Bo Zhang^2,*, Junfeng Xie¹, Jinrui Deng¹, MifengZhao², Ruijing Jiang¹, Yushan Zheng¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1709-1720, 2023, DOI:10.32604/fdmp.2023.025513

Abstract Pitting corrosion often occurs due to the presence of various corrosive substances, such as CO₂ and H₂S, in the pipe service environment. As a result of this process, the residual strength of oil pipes is reduced and this can compromise the integrity of the entire pipe string. In the present work, a model is introduced on the basis of the API579 standard to determine the so-called stress concentration coefficient. The model accounts for pitting corrosion shapes such as shallow semi-circles, semi-circles, and deep semi-circles. The relationship between the corrosion pit depth and opening diameter and the residual strength of the… More >

Yanxian Wu¹, Shouming Zhong¹, Zhigang Guan¹, Lin Song¹, Kun Li², Jiarui Sun², Yuqiang Xu^2,*, Maochuan Tu³, Chaobin Fan³, Jinbin Yang⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 261-271, 2023, DOI:10.32604/fdmp.2023.020076

Abstract A three-dimensional model for the numerical simulation of casing-cement behavior is used to investigate residual strength in the perforated casing of ultra deep wells. The influence of the hole diameter, hole density and phase angle on the residual strength of the casing under non-uniform stress and fracturing conditions is revealed through the consideration of different perforation parameters. It is shown that the residual strength of the casing increases with the hole diameter and periodically changes with the hole density; the phase angle is the main factor that affects the residual strength of the perforated casing, and the perforation should be… More >

Jingpeng Wang¹, Wei Zhang¹, Zhiwei Lin¹, Lin Song¹, Shiyuan Xie¹, Qi Liu², Wei Wang², Tao Yang², Kai Xu², Meng Li², Yuqiang Xu^3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 105-116, 2023, DOI:10.32604/fdmp.2023.020049

Abstract An uncertainty analysis method is proposed for the assessment of the residual strength of a casing subjected to wear and non-uniform load in a deep well. The influence of casing residual stress, out-of-roundness and non-uniform load is considered. The distribution of multi-source parameters related to the residual anti extrusion strength and residual anti internal pressure strength of the casing after wear are determined using the probability theory. Considering the technical casing of X101 well in Xinjiang Oilfield as an example, it is shown that the randomness of casing wear depth, formation elastic modulus and formation Poisson’s ratio are the main… More >

Ei Yamamoto^1,*, Yuki Tanifuji², Masaya Nishimoto², Yuki Kawamura²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 17-17, 2021, DOI:10.32604/icces.2021.08434

Abstract Bone tissue is a viscoelastic material which shows time-dependent mechanical manner. Moreover, it is known that bone microdamage is generated by physiological normal mechanical loading in vivo [1-3]. In order to know basic insight into the adverse effects of creep loading on bone strength, in the present study, we focused on the mechanical behavior of cortical bone after nondestructive creep loading at high stress magnitude. Cylindrical specimens were obtained from cortical bone in the longitudinal and tangential direction of bovine femur. We statically applied a compressive stress to the specimens (creep group) for 24 hours. The specimens without creep loading… More >

A. Rama Chandra Murthy¹, G.S. Palani¹, Nagesh R. Iyer¹

Structural Durability & Health Monitoring, Vol.5, No.3, pp. 201-226, 2009, DOI:10.3970/sdhm.2009.005.201

Abstract This paper presents methodologies for residual strength evaluation of metallic structural components under fatigue loading. Structural components include plate panels of different crack configurations with and without stiffeners. For stiffened panels, stress intensity factor (SIF) has been computed by using parametric equations based on numerically integrated modified virtual crack closure integral (NI-MVCCI) technique. As a part of residual strength evaluation, remaining life has also been predicted by using standard crack growth models. Various methodologies for residual strength evaluation, namely, plastic collapse condition, fracture toughness criterion and remaining life approach have been described. From the studies, it has been observed that… More >