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| 1 | 基于能量耗散的岩石脆性评价方法显示文摘脆性评价是页岩气钻井以及压裂工艺设计的重要环节.然而,现今对于脆性的定义十分模糊,且脆性评价的方法没有成熟的理论作为支撑.本文以岩石应力应变关系为基础,采用能量法来进行储层岩石脆性评价.根据断裂力学裂纹尖端的非线性场理论,以前端区作为尖端特殊的屏蔽构型,来描述储层岩石在断裂过程中能量的耗散.通过计算本征内聚力与前端区稳态阻力比值来表征储层岩石的脆性指数.研究表明,能量耗散相对越大,岩石的脆性指数越低,其塑性特征表现得越明显.基于能量耗散的储层岩石脆性评价是分析岩石力学特性的重要内容,也为压裂选层提供了重要依据. | 陈昀 金衍 陈勉 | 2015 | 力学学报2015，47，6： | 24 |
| 2 | 中国页岩气藏压裂的关键科学问题显示文摘水力压裂技术的提高是保障页岩气高效环保开发的重要途径.本文概述了中美页岩气藏在工程地质、作业环境和技术需求方面的差异.分析表明,中国页岩气藏埋深普遍偏大、闭合压力高、地貌复杂、建井成本高以及水资源匮乏,与美国存在较大差异.针对这些特殊的压裂条件,提出了我国页岩气藏压裂亟待解决的4个关键前沿科学问题:(1)井工厂模式下页岩缝网非平面、非线性动态扩展机理;(2)复杂缝网扩展过程中支撑剂的空间运移和沉降机理;(3)热-流-固三场非线性耦合作用下的页岩气藏重复造缝机理;(4)无水压裂介质流变调控机制与造缝机理.针对各关键科学问题综述了其研究进展和发展方向,对研发原创性的页岩气压裂技术具有重要的理论指导意义. | 赵金洲 尹庆 李勇明 | 2017 | 中国科学:物理学、力学、天文学2017，47，11： | 8 |
| 3 | Research on the nanometric machining of a single crystal nickel via molecular dynamics simulation显示文摘Molecular dynamics simulations are employed to study the nanometric machining process of single crystal nickel. Atoms from different machining zones had different atomic crystal structures owing to the differences in the actions of the cutting tool. The stacking fault tetrahedral was formed by a series of dislocation reactions, and it maintained the stable structure after the dislocation reactions. In addition, evidence of crystal transition and recovery was found by analyzing the number variations in different types of atoms in the primary shear zone, amorphous region, and crystalline region. The effects of machining speed on the cutting force, chip and subsurface defects, and temperature of the contact zone between the tool and workpiece were investigated. The results suggest that higher the machining speed, larger is the cutting force. The degree of amorphousness of chip atoms and the depth and extent of subsurface defects increase with the machining speed. The average friction coefficient first decreases and then increases with the machining speed because of the temperature difference between the chip and machining surface. | GONG Ya Dong ZHU Zong Xiao ZHOU Yun Guang SUN Yao | 2016 | Science China(Technological Sciences)2016，59，12： | 4 |
| 4 | 冲击加载下纯钛微观塑性变形的分子动力学模拟显示文摘激光冲击强化利用激光冲击波力学效应可提高金属材料力学性能,现有实验手段难以测量波后动态物理参量、局部动态力学量以及微观组织动态运动过程。采用分子动力学方法,在300K初始温度下对纯钛进行冲击模拟,观察到冲击加载下冲击波在纯钛中传播的动态双波结构,得到了加载过程中的力学量动态变化以及力学作用下孪晶的动态生长过程。塑性变形过程中,由于位错的塞积和释放,正应力上升的同时剪切力和流变应力不断下降,形成平行孪晶栅。在受冲击表面观察到了极薄的非晶层,其形成与超高应变率塑性变形和动态再结晶相关,且孪晶和非晶层结构均与透射电子显微镜结果吻合较好。 | 陈亚洲 周留成 何卫锋 罗思海 焦阳 庞澄清 刘鹏 | 2016 | 中国激光2016，43，8： | 3 |
| 5 | 含三晶交多晶体沿晶断裂数值建模方法研究显示文摘利用内聚力模型模拟多晶体的沿晶断裂,建立符合实际情况的有限元模型是一个难点。使用Matlab,Python语言和Abaqus混合编程,提出了一套简单快速生成晶粒尺寸符合对数正态分布的Voronoi几何模型的算法;通过编写代码插入节点单元,实现了在界面之间批量插入了零厚度内聚力单元,首次解决了三个零厚度内聚力单元界面处(三晶交)出现的空穴问题,弥补了内聚力模型缺陷;通过二次开发实现了有限元分析的全部过程的自动化,包括赋予材料属性,材料取向、载荷施加,模型求解等。最后以多晶铝为例,使用该方法模拟了在没有初始损伤下多晶铝的沿晶断裂过程,结果表明使用该方法准确可靠,能真实地反映随机微观晶粒的裂纹萌生与扩展过程。 | 史君林 赵建平 | 2018 | 机械强度2018，40，4： | 3 |
| 6 | Size and strain rate effects in tensile strength of penta-twinned Ag nanowires显示文摘Penta-twinned Ag nanowires(pt-AgNWs) have recently attracted much attention due to their interesting mechanical and physical properties. Here we perform largescale atomistic simulations to investigate the influence of sample size and strain rate on the tensile strength of pt-AgNWs. The simulation results show an apparent size effect in that the nanowire strength(defined as the critical stress for dislocation nucleation) increases with decreasing wire diameter. To account for such size effect, a theoretical model involving the interaction between an emerging dislocation and the twin boundary has been developed for the surface nucleation of dislocations. It is shown that the model predictions are in quantitative agreement with the results from atomistic simulations and previous experimental studies in the literatures. The simulations also reveal that nanowire strength is strain-rate dependent, which predicts an activation volume for dislocation nucleation in the range of 1–10b^3,where b is the magnitude of the Burgers vector for a full dislocation. | Xuan Zhang Xiaoyan Li Huajian Gao | 2017 | Acta Mechanica Sinica2017，33，4： | 3 |
| 7 | 双磨粒抛光单晶Si的分子动力学模拟显示文摘目的通过分子动力学(MD)模拟,获得双金刚石磨粒抛光单晶Si的去除机理。方法采用一种新的单晶硅三体磨粒抛光方法,测试双磨粒的抛光深度和横向/纵向间距对三体磨粒抛光的影响,从而获得相变、表面/亚表面损伤等情况,并获得抛光过程中温度及势能的变化情况。结果对比抛光深度为1、3 nm时配位数的情况,发现抛光深度为1 nm时,抛光完成时相变的原子数是4319,而抛光深度为3 nm时,相变原子数为12516。随着磨粒在Si工件表面抛光深度的加深,抛光和磨蚀引起的相变原子和损伤原子的数目增加。仿真结果还表明,单晶Si相变原子的种类和数目随磨粒横向间距的增加而增加,随着纵向间距的增加反而减少。系统的初始温度设为298 K,抛光深度为1 nm时,抛光完成时的温度是456 K,而抛光深度为3 nm时,温度是733 K。抛光完成时,纵向组和横向组的温度仅相差30~40 K。在抛光深度、横向间距和纵向间距3个对照组中,抛光深度对亚表面损伤的影响最大。抛光深度为3 nm时,亚表面的损伤深度最大,从而导致更多的材料从单晶Si工件表面去除。结论双磨粒的抛光深度和间距不仅对硅的表面微观结构产生影响,还对相变产生影响。模拟参数相同时,较大的抛光深度和横向间距下会产生更多的相变原子,因此相变受抛光深度的影响最大,受纵向间距的影响最小。 | 岳海霞 戴厚富 胡洋 周玉琪 | 2021 | 表面技术2021，50，9： | 1 |
| 8 | 多晶体材料微结构二维有限元建模显示文摘多晶体微结构有限元建模是多晶体金属材料研究的重要内容之一。针对传统方法应用的局限性以及难以精确建模问题,提出一种新型多晶体材料微结构建模方法。首先根据指定晶粒尺寸分布规律生成权圆,重点分析常规圆产生方法和依据干涉圆的干涉类型生成新圆,然后对各权圆进行边界划分,最后基于四种指定概率密度函数并结合Ansys软件进行多晶体有限元建模和网格划分实验。该方法能根据多样化的晶粒尺寸分布在较小的误差范围内建立微结构模型,有助于提高仿真的精确性和可靠性,且操作简捷。 | 陈震 周金宇 朱福先 | 2017 | 机械强度2017，39，4： | 1 |
| 9 | 基于分子动力学模拟的纳米铝板力学性能与缺陷演化过程的尺寸效应研究显示文摘采用分子动力学方法模拟了不同分子动力学模型尺寸对含初始裂纹缺陷纳米单晶铝板在拉伸载荷作用下的裂纹缺陷演化过程的影响。结果表明:随着模型尺寸增大,材料的屈服应力减小,屈服点提前,断裂韧性提高。在弹性阶段,材料变形与体系内部原子的点缺陷和面缺陷相关;在塑性变形阶段,材料变形与位错增殖和滑移相关。裂纹尖端处应力集中是裂尖附近晶体结构发生相变的原因,能量在相变后释放导致应力松弛所致。 | 王路生 丁军 宋鹍 刘泊 黄霞 | 2019 | 机械强度2019，41，2： | 0 |
| 10 | Effective property of piezoelectric composites containing coated nano-elliptical fibers with interfacial debonding显示文摘Based on both the spring layer interface model and the Gurtin-Murdoch surface/interface model,the anti-plane shear problem is studied for piezoelectric composites containing coated nano-elliptical fibers with imperfect interfaces.By using the complex function method and the technique of conformal mapping,the exact solutions of the electroelastic fields in fiber,coating,and matrix of piezoelectric nanocomposites are derived under far-field anti-plane mechanical and in-plane electrical loads.Furthermore,the generalized self-consistent method is used to accurately predict the effective electroelastic moduli of the piezoelectric nanocomposites containing coated nano-elliptical fibers with imperfect interfaces.Numerical examples are illustrated to show the effects of the material constants of the imperfect interface layers,the aspect ratio of the fiber section,and the fiber volume fraction on the effective electroelastic moduli of the piezoelectric nanocomposites.The results indicate that the effective electroelastic moduli of the piezoelectric nanocomposites can be significantly reduced by the interfacial debonding,but it can be improved by the surface/interface stresses at the small scale,which provides important theoretical reference for the design and optimization of piezoelectric nanodevices and nanostructures. | Yu Chen Junhong Guo | 2022 | Applied Mathematics and Mechanics(English Edition)2022，43，11： | 0 |
| 11 | Molecular dynamics study on the effect of temperature on HCP→FCC phase transition of magnesium alloy显示文摘To explore the effect of temperature on the phase transformation of HCP→FCC during compression, the uniaxial compression process of AZ31 magnesium alloy was simulated by the molecular dynamics method, and the changes of crystal structure and dislocation evolution were observed. The effects of temperature on mechanical properties, crystal structure, and dislocation evolution of magnesium alloy during compression were analyzed. It is concluded that some of the Shockley partial dislocation is related to FCC stacking faults. With the help of TEM characterization, the correctness of the correlation between some of the dislocations and FCC stacking faults is verified. Through the combination of simulation and experiment, this paper provides an idea for the in-depth study of the solid-phase transformation of magnesium alloys and provides reference and guidance for the design of magnesium alloys with good plasticity and formability at room temperature. | Chun Xue Shuai Li Zhibing Chu Qianhua Yang Yugui Li Lifeng Ma Leifeng Tuo | 2023 | Journal of Magnesium and Alloys2023，11，10： | 0 |
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