Beifeng Lv, Na Li^*, Haibo Kang, Yanting Wu, Ben Li, Wei Wang

Journal of Renewable Materials, Vol.10, No.10, pp. 2669-2683, 2022, DOI:10.32604/jrm.2022.019418

Abstract In order to study the modification effect of recycled sand on cement reinforced waste slurry (CWS), triaxial test, scanning electron microscope test and X-ray diffraction test were carried out. The mechanical test of recycled sand and cement reinforced waste slurry (RCWS) shows that the deviatoric stress–strain curve of RCWS samples changes from hardening type to softening type with the increase of recycled sand content; the peak stress increases with the increase of recycled sand content; recycled sand can enhance the shear strength of CWS by increasing both cohesion and internal friction angle. The microscopic test shows that recycled sand can… More >

Pei Zou¹, Zhiqiang Huang^1,*, Yian Tong², Leichuan Tan³, Rui Li⁴, Kai Wei^1,5, Deng Qiao^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.3, pp. 689-699, 2022, DOI:10.32604/fdmp.2022.019470

Abstract The sealing integrity of cement sheath in offshore wells is seriously threatened under high-temperature conditions, resulting in gas channeling and other problems. Given the lack of experimental results, in this study relevant samples of a cement slurry sealing section of a typical offshore high-temperature well have been prepared and analyzed. In particular, the mechanical properties have been assessed with a triaxial pressure servo instrument and a high-temperature curing kettle. The density and the Poisson’s ratio of the samples have also been tested. The stress-strain curve has been drawn to obtain the elastic modulus and the compressive strength. The rock brittleness… More >

Tongming Qu¹, Shaocheng Di², Y. T. Feng^1,3,*, Min Wang⁴, Tingting Zhao³, Mengqi Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 129-144, 2021, DOI:10.32604/cmes.2021.016172

Abstract This study presents an AI-based constitutive modelling framework wherein the prediction model directly learns from triaxial testing data by combining discrete element modelling (DEM) and deep learning. A constitutive learning strategy is proposed based on the generally accepted frame-indifference assumption in constructing material constitutive models. The low-dimensional principal stress-strain sequence pairs, measured from discrete element modelling of triaxial testing, are used to train recurrent neural networks, and then the predicted principal stress sequence is augmented to other high-dimensional or general stress tensor via coordinate transformation. Through detailed hyperparameter investigations, it is found that long short-term memory (LSTM) and gated recurrent… More >

Qian Wang^1,#,*, Zhaozhao Liu^1,2,#,*, Xiumei Zhong¹, Zhongnan Gao¹, Fuqiang Liu²

Journal of Renewable Materials, Vol.9, No.3, pp. 523-540, 2021, DOI:10.32604/jrm.2021.014114

Abstract To effectively improve the poor engineering properties of loess and enhance its seismic performance, the industrial by-product lignin is used as a modified material. Based on lots of dynamic triaxial tests, the dynamic elastic modulus and damping ratio of lignin-modified loess were tested. The effects of lignin content on the dynamic elastic modulus and damping ratio of lignin-modified loess were analyzed. Combined with scanning electron microscopy (SEM) and X-ray diffraction (XRD), the microscopic mechanism of lignin to improve the dynamic properties of loess was studied. The results show that lignin can effectively modify the dynamic deformation of loess under dynamic… More >