The dynamic torsional buckling and post-buckling of elasto-plastic circular cylindrical shell isstudied.By the usage of the Bodner-Partom constitutive relation,the present visco-plastic problem is treat-ed as an orthotropic elastic problem.Based on the nonlinear large deflection shell therory,the governingdynamic buckling equation is solved by the Runge-Kutta method,and the critical buckling stress is deter-mined by the B-R criterion.The present paper is mainly focused on the imperfection sensitivity,the strainrate sensitivity,and the dynamic post-buckling characters for the shell loaded dynamically with a constantshear strain rate.Numerical results show that the critical shear stress and imperfection sensitivity will in-crease with the increase of strain rate.It is found that the elastic buckling stress is more sensitive toimperfection than the visco-plastic buckling.The present research also reveals some dynamic post-bucklingcharacters for the cylindrical shell,and it is shown that the shell will vibra 相似文献
The Suzhou granite suite is the anorogenic product, which is located on the inactive continental margin of east China. It
was emplaced about 141 Ma ago, occurring as a stock with a polygonal outline on the surface, belonging to alkali potash-feldspar
granites with K2O > Na2O, Reit’s alkali coefficient = 0.694, SiO2 = 74.95, and Al2O3/(K2O + Na2O)mol= 1. Besides K and Na, Li and Rb are also rather high. Highlycharged metals such as Zr, Nb, REE, Y, Sn, Th, Ga and Zn are 10,
or even 50 times higher than those in the ordinary granites. Halogen elements such as F and Cl are high in abundance with
F = 2700 ppm and Cl = 170 ppm on average. The abundances of deep-source elements such as Ti, Al, Ca, Mg and P are relatively
low, with A12O3 = 12.65% and Ca + Mg < 1%. High Ga and low Al contents are typomorphically characteristic of A type granites.
Biotite in the rocks is, for the most part, annite, usually filling in quartz and feldspar crystals, indicating that the crystallization
of magma proceeded under relatively anhydrous condition.
More than 40 kinds of accessory minerals have been identified, of which the mantle-derived mineral chrompicotite and moissanite
is of great interest.
Two different intrusions, the major and supplementary intrusions, can be distinguished in the granite suite. The rock-forming
temperature is estimated to be 810°C, pressure 2.5 kbars, pH 8.1,18O/16O low(δ18OWR = 6.19‰), andfo2= 10−16. The abundances of REE are high and Eu depletion is remarkable (δEu = 0.24).
A variety of mineral deposits related to the Suzhou granite suite have been recognized. 相似文献
Lin, Z.G. and Wang, S.J., 1988. Collapsibility and deformation characteristics of deep-seated loess in China. Eng. Geol., 25: 271–282.
As part of a comprehensive research program, laboratory tests were conducted on samples of deep-seated loess from different locations of the loessial regions of northern China, including Shaanxi, Gansu, Shanxi and Honan Provinces. The information thus acquired on some aspects of the engineering properties of the samples, such as the unit collapse-pressure relationships, the initial collapse pressure versus the “preconsolidation pressure” and deformation–pressure characteristics, is interesting and may prove useful to geotechnical engineers who work on projects on water-poor plateaux or high river terraces in loessial regions throughout the world. 相似文献
Six types of “molecular fossil” indicators are summarized, by which the sources of organic matter (OM) in the sedimentary
rocks of the Lower Tertiary Shahejie Formation in the Dongpu Basin can be traced and the redox and paleosalinity conditions
restored. 相似文献