Papers by Ananth Kumar
It is shown that centrifugal stiffening effects in rotating beams can be countered by spanwise st... more It is shown that centrifugal stiffening effects in rotating beams can be countered by spanwise stiffness variation for a given mode. Smart materials such as magnetorheological elastomer can be used to vary the stiffness in a manner such that a given mode is destiffened. The flexural stiffness functions are demonstrated using a p-version finite element rotating beam code and represent a multifunctional rotating structure concept which can be used for active stiffness control.
Journal of Applied Mechanics-transactions of The Asme, 2009
In this paper we look for a rotating beam, with pinned-free boundary conditions, whose eigenpair ... more In this paper we look for a rotating beam, with pinned-free boundary conditions, whose eigenpair (frequency and mode-shape) is same as that of a uniform non-rotating beam for a particular mode. It is seen that for any given mode, there exists a flexural stiffness function (FSF) for which the i th mode eigenpair of a rotating beam with uniform mass distribution, is identical to that of a corresponding non-rotating beam with same length and mass distribution. Inserting these derived FSF's in a finite element code for a rotating pinned-free beam, the 2 Korak Sarkar, Ranjan Ganguli frequencies and mode shapes of a non-rotating pinned-free beam are obtained. For the first mode, a physically realistic equivalent rotating beam is possible, but for higher modes, the FSF has internal singularities. Strategies for addressing these singularities in the FSF for finite element analysis are provided. The proposed functions can be used as test functions for rotating beam codes and also for targeted destiffening of rotating beams.
Conference Presentations by Ananth Kumar
54th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, 2013
Pin reinforced foam cores with composite facesheets offer a viable means of structural constructi... more Pin reinforced foam cores with composite facesheets offer a viable means of structural construction owing to their low weight and high stiffness and strength. In this paper, various models are introduced to estimate the stiffness and strengths of such a sandwich structure, called K-Cor™, under out-of-plane compressive loading conditions. ince the reinforcing pins have a high modulus compared to the modulus of the facesheet in the transverse direction, the pins indent into the facesheets affecting the overall compressive stiffness of the sandwich structures. Models incorporating this interaction are constructed and their compressive properties are compared with experimental results for various sandwich specimens. The effect of pin locations and size of the sandwich on its compressive properties is also investigated.
Uploads
Papers by Ananth Kumar
Conference Presentations by Ananth Kumar