国家自然科学基金委雷源忠研究员来校讲学

12月8日,应数字制造装备与技术国家重点实验室主任丁汉教授邀请,国家自然科学基金委雷源忠研究员来校指导工作,为机械学院师生作了题为"制造     

利用吴方法求解3自由度并联机器人位置正解

首次利用吴方法求解一种典型的3自由度并联机器人的位置正解,将利用传统方法所得到的32次方程降为一个16次方程,提高了计算效率.在计算过程中,避免了增根的产生.得出对于这一类问题的普遍数学方法,为利用吴方法计算并联结构的正解提供了范例.     

Mechanical analysis of functionally graded plates based on the input data of metallographic diagrams

A microelement method for scale-span analysis of material microstructure and member macro response has been proposed. Instead of material parameter input for traditional mechanical analysis, the method is based on the input of metallographic diagram information. In order to express the material microstructure, this method arranges concentrated microelements in ordinary finite element before calculation, and transfers the node degrees of freedom of each microelement into the ones of the same finite element via compatibility conditions. This method can realize direct transition analysis from material microstructure to macro responses of members, while computation elements and degrees of freedom are equal to those of ordinary FEM. Based on the complicated microstructure diagrams proposed by material metallographic diagram, the mechanics responses of functionally graded plates are calculated and 3-D distributions of macro-mechanical variables and identical stress lines tendency on microstructure are given.     

Numeration and type synthesis of 3-DOF orthogonal translational parallel manipulators

Low-degree-of-freedom （Low-DOF） parallel manipulators （PMs） have drawn extensive interests, particularly in type synthesis in which two main formal approaches were established by using the reciprocal screw system theory and Lie group theory. This paper aims at numeration and type synthesis of orthogonal translational parallel manipulators （OTPMs） by resorting to an integration of the group- based method and graphical representation of the topology. For this purpose, the concept of Cartesian DOF-characteristic matrix, orig- inated from displacement subgroup and displacement submanifold, is proposed. A new approach based on the combination of the atlas of Cartesian DOF-characteristic matrix and the displacement group-theoretic method is addressed for both exhaustive classification and type synthesis of OTPMs. The proposed approach is prone to construct an orthogonal structure and is easy to realize the complete classification and exhaustive enumeration of this class of low-DOF PMs.     

磁性液体密封结构中漏磁的研究

为了研究磁性液体密封结构几何参数的变化对漏磁场的影响规律,选取不同的密封间隙、极齿宽度、齿槽宽度、齿槽深度及密封级数建立物理模型,用有限元方法计算各模型的漏磁场.结果表明在密封结构的轴向和径向距离上存在某一临界值,在临界值的两侧,漏磁场磁感应强度随密封结构几种几何参数的变化趋势不同:在轴向距离大于临界值时,轴向漏磁场磁感应强度随间隙的增大而增大,随级数的增加而减小,随齿宽的增大而减小,随槽宽和槽深的增大而增大;在径向距离小于临界值时,径向漏磁场磁感应强度随间隙的增大而减小,随级数的增加而增大,随齿宽的增大而增大,随槽宽的增大而增大,随槽深的增大而减小;径向距离大于临界值时的情况与小于临界值时的情况刚好相反.     

Dynamic Characteristic Study of Ball Screw Feed Drive Systems Based on Multi-flexible Body Model

A new ball screw dynamic model was developed under the adequate consideration of the interaction in the screw-nut assembly （not only the mutual-coupling factors but also the self-coupling factors） . Based on this model,the multi-flexible body （MFB）dynamic model of ball screw feed drive system was then founded in order to take full account of the influencing factor of system flexibility and study the dynamic behaviors of the whole mechanical transmissions. Moreover,the MFB based state space modeling was proposed by modal state space method, which extraced the eigenmodes of more dominant modes and applied them into an MFB state space model,and realized the integrated model of servo drives and MFB mechanical transmissions more effectively and efficiently. In conclusion,the comparisons between simulations and experimental results show： the stiffness formulation of the ball screw assembly derived above is a suitable method for achieving accurate MFB models of ball screw mechanical transmission systems,this proposed MFB model is valid,and the integrated model of ball screw feed drive system is accurate and reliable. All these provide the important approaches and guidelines for dynamic characteristic study and selection of control parameters in the machine tool design period.     

物种机械学种性漂移研究

提出了用于研究物种机械学种性漂移的基本原理，并以水稻早丰9号与双城糯的复合群体为例对之进行了验证。     

微机电系统与微机械学

该文分析了微型机电系统中产生的一系列特殊效应,介绍了微机电系统中新的设计理论和设计方法,以期建立微机械学理论体系。     

陈扬枝教授

陈扬枝(Chen Yang-zhi),汉族,福建尤溪县人。1986年毕业于天津大学机械制造专业,获工学学士学位;1995年毕业于浙江大学机械学专业,获工学博士学位。毕业至今在华南理工大学机械与     

佐治亚理工学院Singhose博士做客机械学院

檪檪檪檪檪4月15-18日,美国佐治亚理工学院机械工程学院副教授William Sing-hose博士访问了我校机械学院,并作了题为《Creative decisions and design:an innovative design course at georgia tech》的报告.