由非对称整数矩阵求解问题实现的冗余信息密码体系

基于整数有限域矩阵方程求解两类非对称矩阵,得到了唯一解的充要条件和解的递推计算式,结合Diffie-Hellman密钥交换协议设计了一种由通信三方（组织者、发送方、接受方）共同参与的冗余信息密码体系,数值实验验证了设计方案的可行性和正确性.     

高速牙轮钻头轴承双金属密封有限元分析

实践表明：三牙轮钻头中只要一只牙轮的轴承先期损坏,就使整个钻头很快失效。钻头的使用寿命几乎直接取决于钻头轴承的寿命,而轴承的寿命在很大程度上又依赖于密封的寿命。针对目前在高转速条件下,三牙轮钻头轴承的双金属密封系统早期失效严重,导致轴承寿命短,钻头失效更换频繁,大大降低了钻井效率,增加了钻井成本的严重问题,本文开展高速牙轮钻头轴承的双金属密封的有限元研究。阐述了仿真研究的模型建立、网格划分、材料定义、接触定义及边界条件等相关问题。分析了双金属密封中橡胶圈的应变、压缩率的变化规律及两金属环密封面的接触压力分布规律。找到了双金属密封结构中两金属环密封面的接触压力分布趋势不合理及橡胶圈压缩率过大的问题,并提出新型双金属密封结构的改进思路,为新型双金属密封结构的设计提供了较可靠的理论依据。该研究对于提高牙轮钻头的使用寿命,降低钻井成本和提升我国石油钻具的技术水平具有重大实用价值和现实意义。     

更换弦杆加固刚架拱桥技术研究与实践

以江西省宜春市老袁河大桥（刚架拱）加固提载工程为实例,依据大桥的病害及其成因,重点研究了拆除并更换部分弦杆加固的技术,以恢复刚架拱的强度与整体性。该桥还同时应用了在大、小节点、斜撑和主拱腿拱脚处外包钢筋混凝土、重建桥面铺装等加固与改造技术,可供出现类似病害的刚架拱桥维修加固参考和借鉴。     

基于GeoStudio的新疆某水库坝基渗流有限元计算

对GeoStudio的特点及地下水渗流分析模块SEEP/W进行了介绍。根据工程地质勘察资料和水文资料,运用SEEP/W模块对新疆某水库蓄水后河床坝基的渗流进行了有限元模拟计算。从计算结果得出,采用防渗墙进行防渗处理是合理有效的,满足大坝坝基防渗设计要求。灌浆帷幕的渗透性和所在岩基的渗透性相差不大,心墙底部灌浆帷幕防渗效果不明显。     

Behaviors and interactions of strengthening and constraint for ductile Nbss matrix in Nb–Si based alloys

The ductile matrix in composites could be strengthened by incorporating brittle inclusions, while the constraint effect for matrix would become more obvious and detrimental to material toughening. The balance between strengthening and toughening was crucial to achieve excellent comprehensive mechanical properties. Upon the basis of microstructure of Nb–Si in situ composites, a unit rectangular cell containing elastic and isotropic Nb₅Si₃ particles was modeled, the Niobium solid solution (Nb_ss) matrix according with the Ramberg-Osgood constitutive relation was recognized as elastic-plastic. For Nb–Si based alloys, the effects of volume fractions of Nb₅Si₃ reinforcements, stress states and interfacial characteristics on the stress-strain field, flow localization and damage evolution were investigated by the finite element method (FEM). Further, the normalized work of rupture (χ) was calculated quantitatively as a function of volume fractions of Nb₅Si₃ phase as well as yield strength of Nb_ss matrix. These results would contribute to acquire more fundamental understanding of the strengthening and constraint effects which were exerted by Nb₅Si₃ reinforcements to ductile Nb_ss matrix, also an instructive guidance for the optimum design of Nb–Si based alloys.     

伊犁河谷平原灌区地下水流数值模拟研究

本论文运用有限差分法,结合研究区域地下水含水介质系统,采用二维非稳定流数学模型对地下水系统进行了数值模拟,对研究区地下水动态变化进行了评价,为今后的地下水资源评价与管理提供了一种有效的分析方法,为相同条件下的其它区域地下水资源的管理提供了科学依据。利用较为成熟的三维可视化地下水分析计算软件GMS的Modnow模块建立研究区地下水系统的数学摸型,分析预测了研究区在现状条件下的地下水运移规律。并据此提出了研究区的盐碱地治理措施和建议以及水资源利用和生态环境保护措施。     

基于ANSYS的工业机器人大臂的有限元静态分析

以自主研发运用于小型工业生产流水线的六关节工业机器人为研究对象。根据其性能和结构要求,确定该机器人结构的总体设计方案,运用Solidworks三维建模软件构建出所分析的机器人大臂的实体模型,并运用ANSYS分析软件完成对大臂的有限元静态分析,分析结果符合设计要求。本文的研究为六关节工业机器人部件设计的合理性和可靠性提供了科学依据,同时在大臂运用于不同负载情况时对其进行优化设计提供了理论依据。     

塔式起重机高强度螺栓力学特性研究

为了分析塔式起重机高强度螺栓的机械特性,采用理论分析和有限元分析对高强度螺栓进行研究,得到了预紧后的螺栓组应力,加载后的螺栓组应力和加载后的螺栓部分应力云图。分析结果表明：计算的安全系数为,比载荷组合B所需安全系数1.34大,螺栓联接具有一定的可靠性。     

橡胶沥青应力吸收层对路面防裂的影响

应用有限元软件ANSYS,采用三维八节点固体单元有限元模型,分析了橡胶沥青应力吸收层的设置对路面防裂的影响,并探讨了应力吸收层的模量和厚度的合理取值。结果表明:设置橡胶沥青应力吸收层可以减少沥青面层在裂缝区的应力集中,增加路面结构的疲劳寿命,延长路面使用年限。     

Mechanical properties of a novel,lightweight structure inspired by beetle’s elytra

A new kind of bio-inspired, lightweight struc- ture was designed and built from carbon fibre prepreg based on the cross-sectional microstructure of a beetle＇s elytra. The compression strength and failure process of the resulting structure was analysed using the finite element method; while at the same time, a quasi-static compression experiment was performed using an electronic universal testing machine to verify the effectiveness and accuracy of this finite element method. This bioinspired structure was compared against a conventional honeycomb structure using FEM, revealing that for a given porosity and load parallel to the axis of the core tubes the respective compressive and specific compressive strengths of the bio- inspired structure are much higher at 84.3 MPa and 194.7 MPa/（g cm^-3）; thus demonstrating that this bioinspired structure has superior compressive capability.