摘要:

AbstractMethods of solution for the nonlinear stress tensor field equations of matter in the creeping motion state are analysed. For homogeneous matter in two space dimensions the problem proves to be equivalent to the construction of symmetrical tensor fields of constant eigenvalue ratio (1− β)/(1+ β) and constant divergence g, where β and g are the internal friction parameter and the specific weight. A nonlinear second order differential equation remains if a modified Airy stress potential is introduced. This equation is solved generally for β21, g ≠ 0 and also for β2=1, g arbitrary. Physically, the corresponding stress fields describe weightless plastic matter and slowly moving anisotropic fluids respectively. For g ≠ 0 classes of new solutions are derived in th

ISSN:0044-2267    

DOI:10.1002/zamm.19900700102

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractIn the present paper two‐dimensional nonlinear elasticity problems subjected to nonmonotone skin friction effects are formulated and studied. General material laws derived from convex superpotentials are assumed. The friction forces are derived from nonconvex superpotentials through the generalised gradient of F. H. Clarke. The resulting variational‐hemivariational inequalities are studied and the existence and approximation of their solution is discussed by an appropriate combination of monotonicity with compactness argume

ISSN:0044-2267    

DOI:10.1002/zamm.19900700103

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19900700107

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractThe dynamic response of orthotropic and transversely‐isotropic flat plates to dynamic transverse loading and in‐plane tensile loads constitutes the main topic of this paper. The dynamic loading conditions considered herein include sine, rectangular and triangular pulses while spatially, they are considered as sinusoidally distributed. The results obtained as per a higher‐order plate theory are compared with their first order transverse shear deformation and classical counterparts. In addition, some results concerning the associated free‐vibration and bi‐axial buckling of such plates are presented and comparisons with some of the available results are u

ISSN:0044-2267    

DOI:10.1002/zamm.19900700108

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19900700109

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractA study is made of the generation and propagation of transient wave motions in a layered elastic medium due to an asymmetric discontinuity of shear stress acting over a finite circular region at the interface of the composite medium. The problem is solved by the joint Laplace and Hankel transforms combined with Cagniard's method for exact evaluation of the integral solution. SurfaceP‐ andSV‐ wave motions are obtained in closed form assuming both dilatational and shear wave velocities are equal in the top finite layer and in the half space. On the other hand,SH‐wave motion for the general case is expressed in a series, each term of which is evaluated exactly by Cagniard's method. It is shown that the solution is oscillatory in nature and the number of oscillations increases with increasing asymmetry and decreasing ratio of the thickness of the upper layer to the radius of the circular region of the applied stress distribution. Some numerical calculation is carried out to investigate the nature of the displacement field as well as the reflected pulses. Numerical results are graphically presented in three dia

ISSN:0044-2267    

DOI:10.1002/zamm.19900700112

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractNatural convection flow and heat transfer induced by a pulsating point heat source, embedded in an unbounded fluid‐saturated porous medium is studied analytically. Solutions for both the velocity and temperature fields are obtained in the form of series expansions in the Rayleigh number based on the permeability of the porous medium and the mean heat generation rate from the source. All discussions are based on the assumption that the flow is governed by Darcy's law and that the thermal Rayleigh number is small. The fluctuating part shows the evolution of different wave patterns. The interaction of the first harmonic fields induce second‐order mean components in the velocity and temperature fields. Analytical expressions are obtained for the second‐order mean in both the velocity and temperature f

ISSN:0044-2267    

DOI:10.1002/zamm.19900700113

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19900700117

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

摘要:

AbstractUntersucht werden lineare Fredholmsche Integralgleichungen zweiter Art mit Kernen, die entlang beliebiger stetiger Kurven mit schwachen Singularitäten behaftet sind. Durch geeignete Transformationen werden sowohl der Kern als auch die Lösung in glatte Funktionen übergeführt. Zur Lösung der transformierten Integralgleichung werden Quadraturen vom Mehrfachinterpolationstyp benutzt, für deren Berechnung nur Funktionswerte des schwach singulären Kernes benötigt werden. Bedingungen für die Konvergenz des Verfahrens werden hergeleitet, und es wird eine spezielle Technik, die auf der Approximation mit Tschebyscheff‐Polynomen basiert, vorgestellt. Der Nutzen dieser Technik wird anhand numerischer Beispiele de

ISSN:0044-2267    

DOI:10.1002/zamm.19900700118

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19900700119

出版商:WILEY‐VCH Verlag    

年代:1990

数据来源: WILEY