Topological distributions and the torsional rigidity of DNA

1986 ◽  
Vol 189 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Stephen D. Levene ◽  
Donald M. Crothers
Keyword(s):  
Author(s):  
Luís Fernando Marzola da Cunha ◽  
Matheus Lisboa Cardoch Valdes ◽  
Rhander Viana ◽  
Danilo dos Santos Oliveira ◽  
Luiz Eduardo Rodrigues Vieira

Author(s):  
István Ecsedi ◽  
Attila Baksa

AbstractThis paper deals with the Saint-Venant torsion of elastic, cylindrically orthotropic bar whose cross section is a sector of a circular ring shaped bar. The cylindrically orthotropic homogeneous elastic wedge-shaped bar strengthened by on its curved boundary surfaces by thin isotropic elastic shells. An analytical method is presented to obtain the Prandtl’s stress function, torsion function, torsional rigidity and shearing stresses. A numerical example illustrates the application of the developed analytical method.


1974 ◽  
Vol 41 (3) ◽  
pp. 658-662 ◽  
Author(s):  
C. W. Bert ◽  
S. Chang

The twisting stiffness of a rectangular cross section consisting of a single row of solid circular cross-section fibers embedded in a matrix is analyzed. The problem is formulated as a Dirichlet torsion problem of a multielement region and solved by the boundary-point least-squares method. Numerical results for a single-fiber square cross section compare favorably with previous relaxation-method results. New numerical results for three and five-fiber composites suggest that the torsional rigidity of a multifiber composite can be approximated from the torsional rigidities of single and three-fiber models.


Author(s):  
Liliya Ilgizyarovna Gafiyatullina ◽  
◽  
Rustem Gumerovich Salakhudinov ◽  
Keyword(s):  

2017 ◽  
Vol 17 (07) ◽  
pp. 1750076 ◽  
Author(s):  
Ai-Rong Liu ◽  
Chun-Hui Liu ◽  
Ji-Yang Fu ◽  
Yong-Lin Pi ◽  
Yong-Hui Huang ◽  
...  

Bending and torsional vibrations caused by moving vehicle loads are likely to affect the traffic safety and comfort for girder bridges with limited torsional rigidity. This paper studies the use of cables made of shape memory alloy (SMA) as the devices of reinforcement and vibration reduction for girder bridges. The SMA cables are featured by their small volume, expedient installation. To investigate their effect on the vibration of girder bridges, theoretical analysis, numerical simulation and experimental study were conducted in this paper. For bending vibration, the governing equations of the girder with and without SMA cables subjected to moving vehicle loads were derived, while for torsional vibration, the finite element (FE) simulations were used instead. The results of bending and torsional vibrations obtained by the analytical approach and FE simulations, respectively, were compared with the experimental ones from model testing. It was confirmed that the SMA cables can restrain the vibration of the girder bridge effectively.


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