Trapping of diffusive particles by rough absorbing surfaces: Boundary smoothing approach

2014 ◽  
Vol 90 (2) ◽  
Author(s):  
A. Skvortsov ◽  
A. Walker
Keyword(s):  
1998 ◽  
Vol 19 (8) ◽  
pp. 657-668 ◽  
Author(s):  
Jianming Hu ◽  
Donggang Yu ◽  
Hong Yan

Author(s):  
Hong Zhou ◽  
Shabaz Ahmed Mohammed

In discrete topology optimization, material state is either solid or void and there is no topology uncertainty caused by intermediate material state. A common problem of the current discrete topology optimization is that boundaries are unsmooth. Unsmooth boundaries are caused by corners in topology solutions. Although the outer corner cutting and inner corner filling strategy can mitigate corners, it cannot eliminate them. 90-degree corners are usually mitigated to 135-degree corners under the corner handling strategy. The existence of corners in topology solutions is because of the subdivision model. If regular triangles are used to subdivide design domains, corners are inevitable in topology solutions. To eradicate corner from any topology solution, a subdivision model is introduced in this paper for the discrete topology optimization of structures. The design domain is discretized into quadrilateral design cells and every quadrilateral design cell is further subdivided into triangular analysis cells that have a curved hypotenuse. With the presented subdivision model, all boundaries and connections are smooth in any topology solution. The proposed subdivision approach is demonstrated by two discrete topology optimization examples of structures.


2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Prabhat Kumar ◽  
Anupam Saxena ◽  
Roger A. Sauer

Topologies of large deformation contact-aided compliant mechanisms (CCMs), with self and mutual contact, exemplified via path generation applications, are designed using the continuum synthesis approach. Design domain is parameterized using honeycomb tessellation. Assignment of material to each cell, and generation of rigid contact surfaces, are accomplished via suitably sizing and positioning negative circular masks using the stochastic hill-climber search. To facilitate contact analysis, boundary smoothing is implemented. Mean value coordinates are employed to compute shape functions, as many regular hexagonal cells get degenerated into irregular, concave polygons as a consequence of boundary smoothing. Both geometric and material nonlinearities are considered. The augmented Lagrange multiplier method with a formulated active set strategy is employed to incorporate both self and mutual contact. Synthesized contact-aided compliant continua trace paths with single, and importantly, multiple kinks and experience multiple contact interactions pertaining to both self and mutual contact modes.


1986 ◽  
Vol 2 (4) ◽  
pp. 369-375 ◽  
Author(s):  
J. C. Schulz ◽  
O. E. R. Heimdahl
Keyword(s):  

2018 ◽  
Author(s):  
Rômulo Montalvão Silva ◽  
Renato Nascimento Elias ◽  
Alvaro Luiz Gayoso de Azeredo Coutinho

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