双剪应力四参数和五参数准则

本文在作者1962年提出的普遍形式强度理论和1983年的广义双剪应力强度理论的基础上,进一步考虑材料强度性质在π平面和拉伸子午线及压缩子午线上的不同变化规律,得出了适用于描述岩土类材料破坏规律的双剪应力四参数准则和双剪应力五参数准则.其特例可适用于金属类材料.研究结果表明,近年来国内外提出的一些著名的强度理论和多参数准则可以作为本文结果的特例或逼近.     

Studies on Wear and corrosion resistances of carbon nitride thin films on Ti alloy

0　IntroductionArtificialarthrosiseshavebeenwidelyusedintheoperatorsclinicalsurgeriesforthepatientswhosearthrosiseswerese riouslyseverelydamaged.Butmostofartificialarthrosisescanon lybeusedforabouttenyearslongduetotheseriousabrasion .Forthisreason ,theimprovementofthelongevityofartificialarthrosisbecomesanimportantsubjectofstudy .TheartificialarthrosisesbeingmadeupofTialloyTC4(Ti 6Al 4V)andthepolythenewithultrahighmolecularweighthavegreatpotentialitiesonim provinglongevitybecauseTC4canreac…     

Optimizing Concurrent Product Development Process Using Genetic Algorithm

0　IntroductionTimesaving,timetomarketandcycletimereductionarethenewgoalsandaimsforenterprisesinordertosuccessfullycompeteintothemodernglobalmarket[1].Thereisnodoubtthatconcurrentconsiderationofproductandprocessdesignimprovesproductqualityandreducesthere-designwork,whichleadstoshorterproductlead-time.Buttheconcurrentdevelopmentfashionbringsaboutmoreobstaclessuchascomplextimeorder,informationandresourceconstrainednatureofrelationshipsbetweenactivitiestothedesignprocess,whichleadtothefactthatiti…     

A Novel Robust Adaptive Fuzzy Controller

For a class of continuous-time nonlinear system, a novel robust adaptive fuzzy controller is proposed by using of Lyapunov method. It is proven that the control algorithm is globally stable, the output tracking-error can convergence to a domain of zero under the assumptions. As a result, the system controlled has stronger robustness for disturbance and modeling error.     

金属塑性变形的双剪应力准则

材料在复杂应力状态下的屈服准则和强度理论,是研究固体力学、材料强度和结构强度的一个重要基础,从1864年到1913年,提出了两个重要的屈服准则,即Tresca和Mises准则。此后,对材料屈服基本准则的研究的进展不多。在点的空间主应力状态中,存在三个主剪应力     

广义双剪应力屈服准则及其推广

材料在复杂应力状态下的屈服准则是材料本构关系研究的最基础的内容,在固体力学、结构强度和结构弹塑性分析中得到广泛的应用。近年来,这些研究又有新的进展。本文在Tresca屈服准则(1864年)、Mises屈服准则(1913年)和双剪应力屈服准则(1961年)等三个现有屈服准则的基础上,提出一个新的广义双剪应力屈服准则。它包含了双剪应力屈服准则、Tresca屈服准则以及介于这二者之间的一族加权双剪应力屈服准则,它们可以分别适用于范围宽广的各种不同材料。     

The Beetles of Tribe Platyopini in China and Description of Two New Species(Coleoptera:Tenebrionidae)

ＴｈｅｔｒｉｂｅＰｌａｔｙｏｐｉｎｉｉｓａｐｅｃｕｌｉａｒｉｎｓｅｃｔｇｒｏｕｐ ,ｗｈｉｃｈｉｓｄｉｓｔｒｉｂｕｔｅｄｉｎＥａｓｔＡｓｉａ ,ＣｅｎｔｒａｌＡｓｉａａｎｄＮｏｒｔｈＡｆｒｉｃａ .Ｔｈｅｓｅｂｅｅｔｌｅｓａｒｅｔｙｐｉｃａｌｉｎｓｅｃｔｓｉｎｄｅｓｅｒｔ .Ｕｐｔｏｄａｔｅ ,35ｓｐｅｃｉｅｓｏｆ 11ｇｅｎｅｒａｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄａｌｌｏｖｅｒｔｈｅｗｏｒｌｄ ,ａｍｏｎｇｗｈｉｃｈ ,4ｓｐｅｃｉｅｓｏｆ 2 ｇｅｎｅｒａ (ａｂｏｕｔ 11.4 %ｏｆｔｈｅｔｏｔａｌ)ａｒｅｋｎｏｗｎｆ…     

Application of Splitting Extrapolation to Stokes Equation

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＳｔｏｋｅｓｅｑｕａｔｉｏｎｈａｓｗｉｄｅ ｒａｎｇｉｎｇｐｈｙｓｉｃａｌｂａｃｋｇｒｏｕｎｄｓ.Ｔｉｌｌｎｏｗ ,ＭａｎｙｐａｐｅｒｓｆｏｒｎｕｍｅｒｃｉａｌｓｏｌｕｔｉｏｎｓｏｆＳｔｏｋｅｓｅｑｕａｔｉｏｎｈａｖｅｂｅｅｎｐｒｅｓｅｎｔｅｄ .Ｂｒｅｚｚｉｅｔａｌ[1] ｈａｖｅａｌｒｅａｄｙｕｓｅｄｔｈｒｅｅｓｔａｂｌｉｚｅｄｍｉｘｅｄｍｅｔｈｏｄｓａｎｄｏｂｔａｉｎｅｄｔｈｅａｐｐｏｒｘｉｍａｔｅｓｏｌｕ ｔｉｏｎｏｆｔｈｅＳｔｏｋｅｓｅｑｕａｔｉｏｎａｎｄｔｈｅｅ…     

On Robust Stability of a Class of Uncertain Nonlinear Systems with Time—Varying Delay

The problem of robust stability of a class of uncertain nonlinear dynamical systems with time-delay is considered. Based on the assumption that the nominal system is stable, some sufficient conditions on robust stability of uncertain nonlinear dynamical systems with time-delay are derived. Some analytical methods and a type of Lyapunov functional are used to investigate such sufficient conditions. The results obtained in this paper are applicable to perturbed time-delay systems with unbounded time-varying delay. Some previous results are improved and a numerical example is given to demonstrate the validity of our results.