Direct measurements of external forces acting on a structure are infeasible in many cases. The Augmented Kalman Filter (AKF) has several attractive features that can be utilized to solve the inverse problem of identifying applied forces, as it requires the dynamic model and the measured responses of structure at only a few locations. But, the AKF intrinsically suffers from numerical instabiliti...

Soft materials have the advantage that their subsurface structure may be imaged utilizing imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography (CT) scans, and optical coherence tomography. In recent decades subsurface displacement fi elds were successfully measured using these imaging modalities. These displacement fi elds are of time-harmonic, transient, or qu...

In this paper, the development of a large-displacement large-strain 3-D finite element model of the vocal fold is reported. A fold is discretized into 720 8-node brick elements with a total of 1001 nodes and 3003 displacement degrees of freedom. The structure has realistic dimensions and geometry. The model includes geometric and material nonlinearities. The geometric nonlinearity appears in th...

This paper presents the 2D and 3D numerical analysis of pullout tests on steel anchorages in concrete blocks using standard and mixed finite elements. A novel (stabilized) mixed formulation in the variables of total strain ε and displacements u is introduced to overcome the intrinsic deficiencies of the standard displacement-based one in the context of localization of strains, such as mesh depe...

It can be learned that the equivalent viscous damping ratio is a crucial parameter in the application of the displacement based (DBD) method. Analytical studies presented here and elsewhere indicate that the equivalent viscous damping ratio is highly dependent on the axial load level. Furthermore, the same can apply for the loading type; namely, seismic and blast loads. Based on research findin...

An efficient method for the simulation of strained heteroepitaxial growth with intermixing using kinetic Monte Carlo is presented. The model used is based on a solid-on-solid bond counting formulation in which elastic effects are incorporated using a ball and spring model. While idealized, this model nevertheless captures many aspects of heteroepitaxial growth, including nucleation, surface dif...

In this paper we present a new mixed variational formulation for the problem of linear elastostatics. Our formulation is very similar to the classical HellingerReissner formulation, but appears superior for finite element discretization. To make plain the relation between the Hellinger-Reissner formulation and the present one, we consider first an elastic body occupying a region g? in Euclidean...

This article provides a fully analytical approach for nonlinear equilibrium path of rectangular sandwich plates. The core of structure is made of symmetric cross-ply laminated composite and the outer surfaces are piezoelectric actuators which perfectly bonded to inner core. The structure is subjected to electro-thermo-mechanical loads simultaneously. One side of plate is rested on Pasternak typ...