@article{yuan_he_yang_xu_lu_xu_2024, title={Estimating shear modulus of yarn on impact by lazy learning}, volume={270}, ISSN={["1879-2162"]}, DOI={10.1016/j.ijmecsci.2024.109074}, abstractNote={The shear modulus (G) of a yarn model is of paramount importance for simulating the ballistic behaviours of the yarn-level models in finite element (FE) modelling. However, the G of the filament yarn is difficult to measure in the experiment. This study aims to propose the interpolation-based lazy learning methodology to estimate the G for a homogeneous yarn model under a high-speed impact in FE modelling. A two-step process has been developed, each of which contains an interpolation and a lazy learning approach with the 1-NN (1-nearest neighborhood) algorithm. A Dyneema® yarn model under a high-speed impact is initially developed and the transverse deflections of the model with three different values of G are collected as the input in each step. The input for the second step is based on the G predicted in the first. The transverse deflections of the final estimated G are highly consistent with the analytical counterparts. The methodology has been validated in estimating the G of yarn models with different materials and the G of crimped yarn models in the fabric model, which verifies the universality of the methodology.}, journal={INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES}, author={Yuan, Zishun and He, Jie and Yang, Yaru and Xu, Pinghua and Lu, Zhenqian and Xu, Wang}, year={2024}, month={May} }
 @article{yuan_ma_xu_sun_gu_chen_2023, title={A numerical study on stress wave propagation in quasi-isotropic stacks of Dyneema((R)) compliant composite laminates}, volume={312}, ISSN={["1879-1085"]}, DOI={10.1016/j.compstruct.2023.116869}, abstractNote={This study aims to identify the ballistic mechanisms of quasi-isotropic (QI) panels made from compliant composite laminates, focusing on the propagation of various stress waves. Three hypotheses are proposed that in terms of the propagation of stress waves, incorporating ① longitudinal, ② transverse, and ③ bending waves, QI panels would perform better than the aligned (AL) counterparts, based on simplified theoretical analyses to provide a theoretical basis for the study. 2-, 3-, and 4-ply QI panels are found to absorb approximately 23 % more energy than the aligned (AL) counterparts in the ballistic tests. The finite element (FE) models are developed using hierarchical and global-local approaches, and the results are well agreed with the experimental ones. The results elucidate the influence of QI stacks on the propagation of stress waves. The ballistic mechanisms are ultimately explored and elucidated.}, journal={COMPOSITE STRUCTURES}, author={Yuan, Zishun and Ma, Wangfei and Xu, Wang and Sun, Yue and Gu, Binfei and Chen, Xiaogang}, year={2023}, month={May} }
 @article{yuan_zeng_xu_qiu_xu_chen_2021, title={Reverse engineering for estimation of shear modulus for yarn models in finite element modelling for ballistic impact}, volume={274}, ISSN={["1879-1085"]}, DOI={10.1016/j.compstruct.2021.114371}, abstractNote={In finite element (FE) modelling of ballistic performance of fabric, shear moduli of continuous yarn models are usually specified based on approximations and assumptions, despite their significant influence on energy absorption and yarn failure time in a ballistic impact event. This paper applies reverse engineering method for estimating shear modulus G13 of a continuous multifilament yarn model for simulating the ballistic behaviour of the yarn or its fabric. A ballistic event of Dyneema® SK65 yarn model impacted by a projectile travelling at 477 m/s is used to illustrate the establishment of the methodology. The procedure starts by relating G13 and transverse wave velocity (ut) through regression whose correlation factor R2 is 0.999. ut is calculated by the classical Smith equations. The regressed relation and the availability of ut value enable the calculation of G13. The simulated results of the Dyneema® yarn model with such estimated G13 show healthy agreements to the analytical and experimental counterparts in terms of ut and the slope angle of fabric deflection θ. The reverse engineering method has been used for obtaining G13 successfully for yarn models of other materials, e.g. Kevlar KM2 and Zylon®, in simulating their transverse deflection behaviour under the ballistic impact.}, journal={COMPOSITE STRUCTURES}, author={Yuan, Zishun and Zeng, Haoxian and Xu, Wang and Qiu, Jiawen and Xu, Yue and Chen, Xiaogang}, year={2021}, month={Oct} }