A discussion on cohesive zone model formulation for prediction of interlaminar damage in composite laminates is presented in this paper. The degradation of interlaminar mechanical properties is analysed from a physical point of view. Firstly, the damage evolution is evaluated according to the traction-separation law and it is demonstrated that if a linear elastic unloading/ reloading curve is assumed, the softening function must also be linear. Secondly, issues regarding damage onset and fracture criteria in mixed-mode loading are critically addressed and commented. A new set of criteria is proposed, and the limitations of existing criteria are discussed.
Keywords: Cohesive zone modelling | Fracture mechanics | Finite element analysis (FEA) | Delamination | Interface fracture

As a result of progressive use of BIM in effective collaboration and sophisticated data management, the amount of diverse project information is rapidly increased, thus its appearance directly led to revolutionary change in intelligent engineering and production mode. However, it has not been quite advanced in supporting road engineering, especially in conducting a structural calculation for asphalt pavement. Relying on the capabilities of BIM and finite element modeling software ABAQUS, this paper proposed a data conversion interface that can not only present three-dimensional visual modeling but also conduct structural calculation for asphalt pavement. A 3D visualization modeling of asphalt pavement was firstly carried out through Revit modeling software. Afterward, the generated model file (.RVT) was imported into the transferring software YJK, and the model was transformed into a file named INP by the transferring software. Thus, the generated model file (.INP) was analyzed by the software ABAQUS. This study effectively strengthened the BIM with structural analysis capability by developing a conversion interface based on BIM-ABAQUS. The framework provided a supporting platform for the integration of BIM-based highway route design and pavement structural analysis in pavement engineering.
Keywords: Asphalt pavement | Revit 3D model | Data conversion interface | Finite element analysis | Structure calculatio

Bone is a nonlinear, inhomogeneous and anisotropic material. To predict the behavior of bones expert systems are employed to reduce the computational cost and to enhance the accuracy of simulations. In this study, an artificial neural network (ANN) was used for the prediction of displacement in long bones followed by ex-vivo experiments. Three hydrated third metacarpal bones (MC3) from 3 thoroughbred horses were used in the experiments. A set of strain gauges were distributed around the midshaft of the bones. These bones were then loaded in compression in an MTS machine. The recordings of strains, load, Load exposure time, and displacement were used as ANN input parameters. The ANN which was trained using 3,250 experimental data points from two bones predicted the displacement of the third bone (R2 ≥ 0.98). It was suggested that the ANN should be trained using noisy data points. The proposed modification in the training algorithm makes the ANN very robust against noisy inputs measurements. The performance of the ANN was evaluated in response to changes in the number of input data points and then by assuming a lack of strain data. A finite element analysis (FEA) was conducted to replicate one cycle of force-displacement experimental data (to gain the same accuracy produced by the ANN). The comparison of FEA and ANN displacement predictions indicates that the ANN produced a satisfactory outcome within a couple of seconds, while FEA required more than 160 times as long to solve the same model (CPU time: 5 h and 30 min).
Keywords: Artificial neural network (ANN) | Displacement prediction | Finite element analysis (FEA) | Expert system | Long bones | Equine third metacarpal bone (MC3)

This paper deals with the development of an efficient finite element method to study the dynamic characteristics of structures containing fluid. Structural and fluid domains are discretized with 8-node plate/shell element and 20 node brick element respectively. The inviscid incompressible fluid is assumed under irrotational motion. Proper care is taken to eliminate the pressure at fluid–structure interfaces. Mass due to fluid–structure interaction is merged with structural mass and expressed the added mass in terms of inverted fluid stiffness matrix with pre- and postmultiplication of area coefficient matrix. An appropriate node numbering scheme is adopted for idealizing the structural domain and subsequently the fluid domain to gain the computational efficiency and reduction in the storage required for the added mass matrix. The adequacy of the present approach is demonstrated by considering the free vibrations of clamped cantilever plate and clamped-free openended cylindrical tanks and partially filled liquid tankages having common bulk head. Keywords Finite elements  Fluid–structure interaction  Free vibrations  Frequency  Liquid tankages