ANALYSIS ON IMPACT RESPONSES OF UNRESTRAINED PLANAR FRAME STRUCTURE(Ⅰ)—FORMULA DERIVATION

Introduction Recently,therehavebeenconsiderablestudiesontransientresponsesandwave propagationofrestrainedstructureswhicharebeingimpacted[1,2].But,fortheunrestrained structures,therearefewrelativeliteratureshavingbeenpublished.Unrestrainedstructures aremai…     

ANALYSIS ON TRANSVERSE IMPACT RESPONSE OF AN UNRESTRAINED TIMOSHENKO BEAM

A moving rigid-body and an unrestrained Timoshenko beam, which is subjected to the transverse impact of the rigid-body, are treated as a contact-impact system. The generalized Fourier-series method was used to derive the characteristic equation and the characteristic function of the system. The analytical solutions of the impact responses for the system were presented. The responses can be divided into two parts : elastic responses and rigid responses. The momentum sum of elastic responses of the contact-impact system is demonstrated to be zero, which makes the rigid responses of the system easy to evaluate according to the principle of momentum conservation.     

VECTOR ANALYSIS OF SPATIAL MECHANISMS—(Ⅱ) CONFIGURATION ANALYSIS OF SPATIAL MECHANISMS BY MEANS OF THE METHOD OF VECTOR EQUATIONS

In this paper.the configurations of the P-P-G-C and the R-G-C-R Mechanisms are established by the method of vector equa-tions.As in Part1,explicit solutions in terms of givenvectors are obtained,independent of the polynomial equationsof the kind obtained by Chace.     

ON THE STABILITY OF DISTORTED LAMINAR FLOW(Ⅱ)——THE LINEAR STABILITY ANALYSIS OF DISTORTED PARALLEL SHEAR FLOW

Based on the hydrodynamic stability theory of distorted laminar flow and the kind of distortion profiles on the mean velocity in parallel shear flow given in paper [1], this paper investigates the linear stability behaviour of parallel shear flow, presents unstable results of plane Couette flow and pipe Poiseuille flow to two-dimensional or axisymmetric disturbances for the first time, and obtains neutral curves of these two motions under certain definition.     

ON THE STABILITY OF DISTORTED LAMINAR FLOW(Ⅱ)——THE LINEAR STABILITY ANALYSIS OF DISTORTED PARALLEL SHEAR FLOW

Based on the hydrodynamic stability theory of distorted laminar flow and the kind ofdistortion profiles on the mean velocity in parallel shear flow given in paper[1],this paperinvestigates the linear stability behaviour of parallel shear flow.presents unstable results ofplane Couette flow and pipe Poiseuille flow to two-dimensional or axisymmetricdisturbances for the first time,and obtains neutral curves of these two motions under certaindefinition.     

ON THE STABILITY OF DISTORTED LAMINAR FLOW(Ⅲ)—THE NONLINEAR STABILITY ANALYSIS OF DISTORTED PARALLEL SHEAR FLOW

Based on the hydrodynamic stability theory of distorted laminar flow and the kind ofdistortion profiles on the mean velocity in parallel shear flow given in paper[1].this paperinvestigates the nonlinear stability behaviour of parallel shear flow,carries on stabilitycalculation taking account of the perturbations of background turbulence noise undercertain assumption,and obtains some results in accordance qualitatively with those ofexperiment for plane Poiseuille flow and pipe Poiseuille flow.     

THE ANALYSES OF THE THREE-DIMENSIONAL STRESS STRUCTURE NEAR THE CRACK TIP OF MODE Ⅰ CT SPECIMENS IN ELASTICPLASTIC STATE(Ⅱ)—THE ANALYSES OF THE STRESS STRUCTURE

Based on[1],the stress structures of the smooth region and shear lip of thespecimens have been investigated in the paper.The characteristics of the stress structure inthe smooth region have been found that the variable z can separated out;the stressesin the midsection can be obtained by the plane strain FEM results or HRR structuremodified by the stress triaxiality.The effects of load level and thickness on the stressstructure can be reflected by the distribution of CTOD along the thickness direction.The obtained expressions of the stresses are very simple and visualized.The analysesof the stress structure in the shear lip show that the stresses can be obtained bydifferent methods of interpolation to a certain precise degree.A new degree parameter of the plane strain state has been put forward andstudied.The parameter can reflect relatively well the variation of the kind andthickness of the specimen as well as the load level.The fracture parameter has alsobeen investigated to be sure that it can be obta     

AN APPLICATION OF TOPOLOGICAL METHOD TO ANALYSING THE THREE-DIMENSIONAL FLOW IN CASCADES(Ⅱ)-TOPOLOGICAL ANALYSIS ON THE VECTOR FIELD PATTERNS OF SKINFRICTIONS AND SECTION STREAMLINES

With an application of topological analysis,in this paper the skin-friction line patternson compressor and turbine cascade surfaces are depicted and the streamline patterns of thesecondary flow fields in the cross-section of a curved pipe and a turbine cascade are drawnunder given conditions.In addition the structures of vortices within three-dimensionalviscous flow fields in cascades are analysed.