钢管混凝土柱-环扁梁中节点静载试验研究

介绍了钢管混凝土柱-钢筋混凝土环扁梁中节点的构造和基本受力机理,以及环梁、环扁粱节点的静载试验结果.试验结果表明,通过合理设计,环梁、环扁梁节点能有效地传递框架梁、扁梁梁端的剪力和弯矩,具有良好的变形能力.     

LZ50车轴钢疲劳裂纹扩展试验研究

完成了连铸和模铸LZ50车轴钢疲劳裂纹扩展试验,得到了两类LZ50车轴钢的疲劳裂纹扩展曲线。采用Paris公式和另一种全范围表达式研究了两种铸造工艺下LZ50车轴钢的疲劳裂纹扩展规律。研究结果表明:Paris公式仅能描述LZ50车轴钢疲劳裂纹稳定扩展阶段的规律;全范围表达式对LZ50车轴钢的全范围疲劳裂纹扩展规律描述较好,且得到的疲劳裂纹扩展门槛值与试验曲线得到的门槛值接近,相对误差小于3%;连铸LZ50车轴钢的疲劳裂纹扩展速率门槛值低于模铸LZ50车轴钢,其疲劳裂纹扩展性能不如模铸LZ50车轴钢。     

BACKWARD WELLPOSEDNESS OF NONUNIFORM TIMOSHENKO BEAM EQUATION

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｐｕｒｐｏｓｅｏｆｔｈｉｓｗｏｒｋｉｓｔｏｉｎｖｅｓｔｉｇａｔｅｔｈｅｂａｃｋｗｅｌｌｐｏｓｅｄｎｅｓｓｏｆａｎｏｎｕｎｉｆｏｒｍｂｅａｍｅｑｕａｔｉｏｎｗｉｔｈｂｏｕｎｄａｒｙｃｏｎｔｒｏｌｓ.Ｉｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｉｆｔｈｅｃｒｏｓｓ ｓｅｃｔｉｏｎｄｉｍｅｎｓｉｏｎｓｏｆｔｈｅｂｅａｍｉｓｎｏｔｎｅｇｌｉｇｉｂｌｅｃｏｍｐａｒｅｄｗｉｔｈｉｔｓｌｅｎｇｔｈ ,ｔｈｅｎｉｔｉｓｎｅｃｅｓｓａｒｙｔｏｃｏｎｓｉｄｅｒｔｈｅｅｆｆｅｃｔｏｆｔｈｅｒｏｔａｔｏ…     

损伤粘弹性梁-柱的广义变分原理

从损伤的粘弹性材料的卷积型本构关系出发,建立了在小变形下损伤粘弹性梁-柱的控制方程,提出了以卷积形式表示的损伤粘弹性梁-柱弯曲问题的泛函,并给出了损伤粘弹性梁-柱的广义变分原理.应用这个广义变分原理,可分别给出梁-柱位移和损伤满足的基本方程,以及相应的初始条件和边界条件.     

对Lagrange中值定理证明方法的讨论

对Lagrange中值定理的证明，在高等数学的传统证法中，通常都是采用引入一个“辅助函数”，将适合定理的函数转换成适合Rolle中值定理的函数的办法．为了进一步开阔思路，更好地理解和掌握Lagrange中值定理，本文给出了行列式证法、旋转变换证法和区间套定理证法等几种证明方法。     

力学模型与软件选用的几个问题

每项工程必须根据所确定的受力模型选取相应的结构程序进行计算和设计。在目前设计行业中，最常见的几个问题是：选用PK程序设计时，未考虑框架柱双向配筋；平面不规则框架仍选用PK程序，而实际应选用TAT程序；对底层框架上部砖混结构，选用了PK程序，实际应选用底层框架设计程序；框架梁抗剪钢筋直接采用PK程序出图结果，而未经分析调整。     

含Dini导数的函数的增减性

以连续归纳法为工具，讨论了含Dini导数的函数的增减性。     

PLC断电时间记录问题的研究

针对连续性较强的生产过程中控制系统断电问题,在以PLC为核心的控制系统中,采用软件方法实现了对系统断电时间的记录,解决了碑酒发酵过程的断续问题.     

Natural Frequency of Full-Prestressed Concrete Beam

Dynamic tests of three bonded and two unbonded full-prestressed concrete beams were carried out.The purpose was to seek the relation between prestressing force and natural frequency.Test results indicate that the frequency of prestressed concrete(PSC)beam increases with the increase in prestressing force approximately.The results are different from the dynamic characteristics of isotropic material beam subjected to compressive axial force which were put forward by Clough et al.The reason is that the beams were considered as isotropic,homogeneous,linear elastic material in the traditional analysis method.However,more accurate results are required in the analysis of frequency of PSC beam.The constitutive mode of PSC member is analyzed based on microstructure of concrete in this paper.The orthotropic linear elastic mode is used to analyze the relation between dynamic frequency and prestressing force of concrete beam,at the same time the equivalent stiffness of prestressed tendon relating to the prestressing force is added to the bending deformation stiffness of the beam.The analytical value agrees well with the test result,indicating that the current analysis method in this paper is feasible to full-prestressed concrete beam.     

论一种新型对注管的设计思路

本提出了克服速调管中散聚效应的一种新型电子器件－对注管的结构方案，并对其中的电子工作机制，器件，工作原理，管制结构以及其主要设计参量进行了分析与探讨，最后提出了该管向毫米波，亚毫米波发展的可能性。