Anssi Karttunen, J.N. Reddy, and Jani Romanoff

Over the past decade or two, the rise of small-scale technologies and the development of novel heterogeneous materials and periodic structures have led to a growing interest in micromechanical modeling of solids. This, in turn, has sparked interest in non-classical theories of continuum mechanics which, unlike the classical one, account for microstructure-dependent small-scale effects that may have an impact on the macro-deformation of a structure. The widely used modified couple-stress theory provides a coherent framework for developing microstructure-dependent structural models such as beams and plates.

In this project, we show that a modified couple-stress Timoshenko beam model can be used to study web-core sandwich beams. In addition, we derive general closed-form solutions and finite elements for the bending of beams and plates based on the modified couple-stress theory. The developed couple-stress based beam finite elements are used to study web-core sandwich beams in different settings.



[1] Romanoff J, Reddy JN. Experimental validation of the modified couple stress Timoshenko beam theory for web-core sandwich panels. Compos. Struct 111 (2014) 130-137.
[2] Romanoff J, Reddy JN, Jelovica J. Using non-local Timoshenko beam theories for prediction of micro- and macro-structural responses. Compos. Struct. (In Press)
[3] Reddy JN, Romanoff J, Loya JA. Nonlinear finite element analysis of functionally graded circular plates with modified couple stress theory. Eur. J. Mech. A-Solids. 56 (2016) 92-104.
[4] Karttunen AT, Romanoff J, Reddy JN. Exact microstructure-dependent Timoshenko beam element. Int. J. Mech. Sci. (In Press).
[5] Karttunen AT, Reddy JN, Romanoff J. Closed-form solution for circular microstructure-dependent Mindlin plates (Under review).