Inertial effects in the theory of dielectric and Kerr effect relaxation of an assembly of non-interacting polar molecules in strong alternating fields. II. The effect of higher-order terms in the distribution function

1988 ◽  
Vol 125 (1) ◽  
pp. 99-118 ◽  
Author(s):  
W.T. Coffey ◽  
S.G. Mcgoldrick ◽  
K.P. Quinn
1969 ◽  
Vol 47 (8) ◽  
pp. 1441-1443
Author(s):  
J. C. Nash ◽  
W. G. Laidlaw

Tunneling through a barrier is calculated with the Wigner distribution function. The use of a simple height-to-width formula for various potential types is illustrated. The effect of higher order terms is also investigated.


2013 ◽  
Vol 586 ◽  
pp. 237-240 ◽  
Author(s):  
Lucie Šestáková

Most of fracture analyses often require an accurate knowledge of the stress/displacement field over the investigated body. However, this can be sometimes problematic when only one (singular) term of the Williams expansion is considered. Therefore, also other terms should be taken into account. Such an approach, referred to as multi-parameter fracture mechanics is used and investigated in this paper. Its importance for short/long cracks and the influence of different boundary conditions are studied. It has been found out that higher-order terms of the Williams expansion can contribute to more precise description of the stress distribution near the crack tip especially for long cracks. Unfortunately, the dependences obtained from the analyses presented are not unambiguous and it cannot be strictly derived how many of the higher-order terms are sufficient.


1990 ◽  
Vol 235 (1-2) ◽  
pp. 141-146 ◽  
Author(s):  
Luc Marleau

Materials ◽  
2003 ◽  
Author(s):  
David A. Jack ◽  
Douglas E. Smith

Orientation tensors are widely used to describe fiber distri-butions in short fiber reinforced composite systems. Although these tensors capture the stochastic nature of concentrated fiber suspensions in a compact form, the evolution equation for each lower order tensor is a function of the next higher order tensor. Flow calculations typically employ a closure that approximates the fourth-order orientation tensor as a function of the second order orientation tensor. Recent work has been done with eigen-value based and invariant based closure approximations of the fourth-order tensor. The effect of using lower order tensors tensors in process simulations by reconstructing the distribution function from successively higher order orientation tensors in a Fourier series representation is considered. This analysis uses the property that orientation tensors are related to the series expansion coefficients of the distribution function. Errors for several closures are investigated and compared with errors developed when using a reconstruction from the exact 2nd, 4th, and 6th order orientation tensors over a range of interaction coefficients from 10−4 to 10−1 for several flow fields.


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