Shang Zhang¹, Jie Wang², Benjamin Rose⁵, Yushan Yang³, Qingfeng Ding¹, Bengang Zhang^4,*, Chunlei Dong^2,*

Journal of Renewable Materials, Vol.11, No.6, pp. 2881-2891, 2023, DOI:10.32604/jrm.2023.028160

Abstract To study the static bending creep properties of glass fiber reinforced wood, glass fiber reinforced poplar (GFRP) specimens were obtained by pasting glass fiber on the upper and lower surfaces of Poplar (Populus euramevicana, P), the performance of Normal Creep (NC) and Mechanical Sorptive Creep (MSC) of GFRP and their influencing factors were tested and analyzed. The test results and analysis show that: (1) The MOE and MOR of Poplar were increased by 17.06% and 10.00% respectively by the glass fiber surface reinforced composite. (2) The surface reinforced P with glass fiber cloth only exhibits the NC pattern of wood… More >

Guangsheng Liu^1,2, Qingming Gan^1,2, Wen Wu³, Haitao Yang^1,2, Yiming Lv^1,2, Wenhao Cui^1,2, Wei Lin^4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1203-1214, 2023, DOI:10.32604/fdmp.2023.022022

Abstract The finite element method has been applied to simulate the dynamics of a water plugging string in a complex horizontal well of a low-permeability oilfield. The force associated with the pipe string and the packer has been determined under the sucking action of the oil well pump. Such analysis has been conducted for a real drilling well, taking into account the process of lifting, lowering, unblocking and water plugging. Comparison between field measured data and simulation data indicates that the model is reliable and accurate. The packer creep effect under different pressure differences has also been investigated in the framework… More >

Jike Gao¹, Fawei Li^2,*, Shangjun Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1173-1187, 2023, DOI:10.32604/fdmp.2022.021140

Abstract Composite fabrics based on Polytetrafluoroethylene (PTFE) polymer displays several notable properties. They are waterproof, windproof, permeable to moisture and thermally insulating at the same time. In the present study, PTFE fibers are used as raw material to make fiber membranes. The film is formed by crisscrossing interconnected fiber filaments and the related air permeability: tensile creep characteristics and other properties are tested. The results show that the pore size, thickness, and porosity of the film itself can affect the moisture permeability of the film. The water pressure resistance of the selected fabric is 8.5 kPa, and the moisture permeability is… More >

Jun Zhou^1,*, Shijie Fang¹, Jinghong Peng¹, Qing Li², Guangchuan Liang^1,*

Energy Engineering, Vol.120, No.1, pp. 221-243, 2023, DOI:10.32604/ee.2022.020317

Abstract Underground energy storage is an important function of all energy supply systems, and especially concerning the seemingly eternal imbalance between production and demand. Salt rock underground energy storage, for one, is widely applied in both traditional and renewable energy fields; and this particular technique can be used to store natural gas, hydrogen, and compressed air. However, resource diversification and structural complexity make the supply system increasingly uncertain with the passing years, leading to great challenges for energy storage facilities in the present, and perhaps going into the future as well. Hence, it is necessary to research the operation stability of… More >

Ali Amiri, Nassibeh Hosseini, Chad A. Ulven^*

Journal of Renewable Materials, Vol.3, No.3, pp. 224-233, 2015, DOI:10.7569/JRM.2015.634111

Abstract Natural fibers have great potential to be used as reinforcement in composite materials. Cellulose, being a critical constituent of natural fibers, provides unquestionable advantages over synthetically produced fibers. Increasing demand for use of bio-based composites in different engineering and structural applications requires proper test methods and models for predicting their long-term behavior. In the present work, the time-temperature superposition principle was successfully applied to characterize creep behavior of flax/vinyl ester composites. The creep compliance vs time curves were determined and shifted along the logarithmic time axis to generate a master compliance curve. The time-temperature superposition provided an accelerated method for… More >

Jundong Yin¹, Lei Wang¹, Baoyin Zhu², Guodong Zhang², Dongfeng Li^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-3, 2022, DOI:10.32604/icces.2022.08750

Abstract High performance martensitic heat resistant steels are widely used in fossil fuel power plant industry due to because of their good creep resistance at high temperatures. In-depth understanding of the high temperature inelastic deformation mechanism of such steels is crucial to ensure the reliable, safe and efficient operation of the power plant [1]. The martensitic steels have a complex microstructure with a hierarchical arrangement, including a collection of packets in the prior austenite grain, blocks in the packet and laths along with dispersed nanoscale strengthening phases (e.g., MX precipitates and carbides). The purpose of this paper is to study the… More >

Yifei Yin, Lirong Qu, Weidong Lu^*, Chengshuai Li

Journal of Renewable Materials, Vol.10, No.6, pp. 1517-1535, 2022, DOI:10.32604/jrm.2022.018149

Abstract Creep test results of glulam members under compression and bending were studied in this paper. The creep tests were conducted to investigate the influence of the stress level and relative eccentricity on the creep deformation of glulam members. The test results showed that the creep deformation trends of glulam members under long-term compression and bending loading were similar; the creep deformation increased with increases in both the stress level and relative eccentricity. However, the relative creep deformation decreased with the increase in both the stress level and relative eccentricity under long-term loading, and a five-parameter creep model was proposed to… More > Graphic Abstract

Nan Guo¹, Jing Ren¹, Ling Li^1,*, Yan Zhao², Mingtao Wu¹

Journal of Renewable Materials, Vol.10, No.1, pp. 183-201, 2022, DOI:10.32604/jrm.2021.015756

Abstract Due to creep characteristics of wood, long-term loading can cause a significant stress loss of steel bars in reinforced glulam beams and high long-term deflection of the beam midspan. In this study, 15 glulam beams were subjected to a 90-day long-term loading test, and the effects of long-term loading value, reinforcement ratio and prestress level on the stress of steel bars, midspan long-term deflection, and other parameters were compared and analyzed. The main conclusions drawn from this study were that the long-term deflection of the reinforced glulam beams accounted for 22.5%, 20.6%, and 18.2% of the total deflection respectively when… 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 >

Nan Guo^1,*, Huajing Xiong¹, Mingtao Wu¹, Hongliang Zuo¹, Fengguo Jiang², Xiaofeng Hou³, Dabo Xin¹

Structural Durability & Health Monitoring, Vol.14, No.3, pp. 229-248, 2020, DOI:10.32604/sdhm.2020.09104

Abstract Creep is an important characteristic of bamboo and wood materials under long-term loading. This paper aims to study the long-term bending behaviour of prestressed glulam bamboo-wood beam (GBWB). For this, 14 pre-stressed GBWBs were selected and subjected to a long-term loading test for 60 days. Then, a comparative analysis was performed for the effects of pretension values, the number of pre-stressed wires, and long-term load on the stress variation of the steel wire and the long-term deflection of the beam midspan. The test results showed that with the number of prestressed wires increasing, the total stress of the steel wire… More >