肋形板梁式液体化工码头桩台结构研究

针对液体化工码头桩台无有轨装卸设备荷载、竖向使用荷载小且水平荷载较大的特点,提出了肋形板梁式液体化工码头桩台结构。通过计算分析及构造处理可以得出,肋形板梁式结构是一种安全可靠、整体性好、预制安装程度高、施工快捷且造价较省的结构形式,具备良好的应用前景,可为实际工程提供一种供比选的结构形式。

三边简支一边固定钢筋混凝土矩形板分析

钢筋混凝土材料是典型的复合材料,其两个方向的配筋一般是不同的,从而导致两个方向的刚度不相同。长期以来在分析钢筋混凝土板时,都采用了各向同性材料的假定,这样的分析方法在理论上是不正确的,计算的结果也与实际情况有较大误差。本文采用正交各向异性弹性理论,分析了三边简支一边固定的钢筋混凝土板在双向线性荷载作用下的挠度,并通过具体算例与有关资料对比,说明采用本方法切实可行,而且级数收敛速度很快,对于挠度计算,可以只取第一项即满足精度要求。本文可供修订规范时参考。

The Influence of Edge Restraining Stiffness on the Transverse Vibrations of Rectangular Plate Structures

This paper presents an analytical study on the influence of edge restraining stiffness on the transverse vibrations of rectangular plate structure. An improved Fourier series method was employed to analyze the transverse vibration of plate structure with general elastically restrained boundary conditions. A linear combination of a double Fourier series and eight auxiliary terms was sought as the admissible function of the flexural displacement of the plate, each term being a combination of a polynomial function and a single cosine series expansion. The auxiliary terms were introduced to ensure and improve the smoothness of the original displacement function and its derivatives at the boundaries. Several numerical examples were given to demonstrate the validity and accuracy of the current solution. The influences of translational and rotational stiffness on the natural frequencies and mode shapes of plate were analyzed by numerical results. The results show that the translational stiffness has bigger influence on the natural frequencies than the rotational stiffness. It is generally well known that little change of the rotational stiffness has little influence on the mode shapes of plate. However, the current work shows that a very little change of rotational stiffness value may lead to a large change of the mode shapes of a square plate structure.

Structure of the Venom Apparatus of Large Carpenter Bees, Xylocopa fenestrata （Fabricius） （Hymenoptera： Apidae）

The venom apparatus in the large carpenter bees, Xylocopafenestrata （Fabricius） （Hymenoptera： Apidae） has been studied It consists of typical parts, i.e., the venom sac, free filament, Dufour gland, sting shaft and accessory sclerites. It is highly sclerotized and concealed by the 7th abdominal tergite and sternite. The venom sac serves as a reservoir for the venom which synthesized by the convoluted gland present in it, which is remarkably uniform to that of ants. The median duct extends from lower portion of venom sac, which measures 2.5 ±0.17 mm （mean ＋ SD） （n = 20） in length. The Dufour gland is a tube-like structure which is inserted in the sting-bulb. The triangular plate is attached at terminal portion of rami, which is in turn attached with lancets. The gonostyli are paired long and tubular structure with 5.29 ± 0.23 mm （n = 20） in length. The sting length is 5.29 ±0.23 mm （n = 20）. The fulcral arm is well-developed with an inverse Y-shaped structure present beneath the sting-bulb. Barbs on the sting shaft are weakly developed in X fenestrata but well developed in ants. The venom apparatus ofX. fenestrata when compared is similar to the bees but differs from that of the wasps and ants.

Nonlinear dynamic buckling of stiffened plates under in-plane impact load

This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.

Re-discussion on the Jiaochang Arcuate Structure, Sichuan Province, and the Seismogenic Structure for Diexi Earthquake in 1933

The Jiaochang arcuate structure is one of the numerous arcuate structural belts in Sichuan. The present paper gives a further argument about the characteristics of that arcuate structure and the new activity of the Songpinggou fault and affirms that the Songpinggou fault is an active fault in the Holocene epoch. The Diexi M 7.5 earthquake took place in 1933 on the west wing of that arcuate structure, near the apex of the arc. Many authors have given quite different opinions about the genetic structure of that earthquake. The authors have made on the spot investigations time and again over recent years. Besides this, the authors have also further studied the shape of intensity contour lines, the distribution characteristics of ground surface seismic hazards, the left lateral dislocation of buildings along the Songpinggou fault, the NW trending ground fissures that developed on the ground surface after earthquake, and so on. On this basis, it is still considered that the seismogenic fault of the 1933 Diexi M 7.5 earthquake was the Songpinggou fault on the west wing of the Jiaochang arcuate structure.

大型模锻液压机机架结构分析研究

概述了我国大型锻压装备的现状与差距,通过对大型模锻液压机机架结构形式及特点的分析研究,提出了我国800 MN大型模锻压机选择C形板机架结构方案。对C形板预紧组合机架的结构设计进行改进,对制造进行技术创新,并对C形板机架强度、刚度、疲劳寿命进行了分析计算和优化。

A geostrophic empirical mode based on altimetric sea surface height

Recent discovery of low-dimensional coherent structure in oceanic currents along with a new merged altimeter product called Absolute Dynamic Topography (ADT) makes it possible to derive subsurface ocean information from satellite remote sensing data.An altimetric geostrophic empirical mode (η-GEM) is developed in this study by projecting hydrographic transects onto the ADT sea surface height coordinate,based on which the four-dimensional thermohaline and velocity structures of oceanic currents are reconstructed from satellite surface observations.In the WOCE/SR3 area,the η-GEM fields capture more than 95% of the total thermal variance.The GEM-derived flow has equivalent-barotropic structure and represents the velocity profile better than traditional dynamic modes.Comparison with mooring observations also demonstrates that the η-GEM provides good estimates of the deep thermohaline fields.

Analytical model for ultimate loading capacities of continuous composite slabs with profiled steel sheets

Composite slabs with profiled steel sheet are widely applied in practical structures now. Plenty of literatures can be available about simply supported composite slabs with single span. However, continuous slabs always exist in high-rise building structures. In order to obtain the ultimate loading capacity of continuous composite slabs, the full scale test on slab specimens with high cost need to be carried out. This paper presented an analytical model for calculating the ultimate loading capacity of continuous composite slabs. Only the small-scale slide block test needed to be carried out for determining some mechanical parameters, resulting in less cost, compared with the conventional m-k test method. Various load conditions and parameters were considered in the analytical model. The comparison between test results and predicted results showed that the proposed method had enough precision. Furthermore, the simplified method was also proposed for practical design.

Statistical analysis of vibration and sound radiation of submerged stiffened rectangular plates

In order to extend the statistical energy analysis(SEA) method to predict the vibration and sound radiation of underwater structures,we mainly analyze the effect of water loading on the key parameters in SEA and propose the approximate expressions of modal density and mean square velocity of submerged plates.With the radiation efficiency of submerged plates previously proposed by us,the modified SEA solutions of the radiated sound power and mean square velocity of submerged stiffened rectangular plates are established.Numerical examples show that the modified SEA solutions are more close to the theoretical solutions than the present SEA solutions,and reflect the mean value or trend of the theoretical solution much better,especially at lower frequencies.An experiment of point-exciting submerged plates was done in a lake.The experiment values show that for both un-stiffened and stiffened plates,the modified SEA solutions have a good agreement while the present SEA solution has considerable error,which validates the established statistical model.