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An experimental study was carried out to examine the impact-induced loads and structural responses of a three-dimensional non-prismatic aluminium wedge. The findings of the experimental study were presented in the first part of this publication, entitled “Slamming loads and responses on a non-prismatic stiffened aluminium wedge: Part I. Experimental study.” This paper describes the second part of the study, which deals with numerical simulations of slamming loads acting on the wedge and its dynamic responses. Two different two-way coupling methods are assessed and compared to simulate the water entry problem. Initially, an explicit nonlinear finite element method with a Multi-Material Arbitrary Lagrangian-Eulerian (MMALE) solver is employed to evaluate the elastic response of the structure following a free-fall water impact. Subsequently, the hydroelastic slamming problem is modelled using a two-way coupled technique with a k-ε turbulence model and implicit unsteady solver for both the fluid and structural domains (Star-CCM+/ABAQUS). The effect of viscosity on slamming loads and responses was examined, and numerical results are compared with experimental data. To investigate the effect of rigidity on structural response and bottom deflection, the wedge was designed with bottom plates of varying thickness. The computed results from the two numerical models and the experimental data are in good agreement. The study concluded that the bottom plates deformation affects hydrodynamic loads during slamming. It is also observed that impact-induced loads depend on the water impact velocity and the flexibility of the bottom plates. This suggests that the slamming pressure increases with an increase in impact velocity and decreases when the structures become more flexible. According to this study, both numerical models are suitable for accurate and efficient computations of hydroelastic slamming; however, the MMALE method results in larger numerical fluctuations.

Indirect bridge health monitoring requires an instrumented vehicle with an accelerometer to scan bridge vibration. The indirect method is more practical than the conventional direct method due to its cost efficiency and mobility. However, the vehicle’s own response may pollute the recorded vertical acceleration signal. This paper utilizes a newly developed contact-point calculation method to show its efficiency to reflect the true vibration of bridges. A finite element model is developed for a vehicle placed in stationary state at mid-span of a bridge that is excited by a moving vehicle. Two cases considering different property of the stationary vehicle and different speed of the moving vehicle are developed. The contact-point response is extracted from the stationary vehicle response using MATLAB. The results show the discrepancy between the stationary vehicle and bridge responses. In contrast, good agreement between the contact-point and bridge responses is presented in the time and frequency domains.

The rigid body force (RBF) generated by fluid movement inside a partially filled tank is of great importance for many tank structures transporting liquid under dynamic conditions. However, accurate prediction of such forces presents a challenge for the designer due to the high level of nonlinearities involved. In this paper, three fundamentally different approaches; Eulerian Volume of Fluid (VOF) approach with three common turbulence models; Smoothed Particle Hydrodynamics (SPH); and Arbitrary Lagrangian–Eulerian (ALE) are used to simulate liquid sloshing responses. The three approaches are implemented across two commercial simulation packages (ANSYS Fluent and Ls-Dyna) and evaluated using the experimental measurement from Yan (2008). A detailed quantitative comparative study on the RBF among various numerical methods are carried out, while a good agreement is found among the converged solution of using the LES turbulence model in Ansys Fluent; SPH and ALE in Ls-Dyna; while the ICFD model presents slower convergence to the experiment result compared to the other solvers. On other hand, all the numerical approaches fail to accurately predict the maximum absolute RBF while the wave is sharply separated from the main domain and this force overprediction/underprediction is dependent on element size, time step size and fluid model. Impulse, rather than absolute maximum RBF is proposed as the main computational characteristic to validate the performance of the baffled/unbaffled transport tanks under fluid sloshing.

The increase in the number of vehicles due to increase in population leads to an increase in the number of accidents. To find a design that keeps occupants as safe as possible by enhancing the energy absorption capabilities and hence decreasing the number of fatalities is taking place. Non-linear finite element is used in this study to predict new design performance and to compare with other conventional S-shaped designs. It was shown that the proposed design increased the specific energy absorption (SEA) by 265% in comparison with the conventional S-Shaped frame design with octagonal geometries and increased in SEA 16% of the S-Shaped with foam filled-square cross-sectional. In this study, the specific energy absorption will take in consideration the energy absorber used is made of mild steel.

The conventional overhead transmission line insulators are usually made of glass and ceramics, but the materials are heavy and bulky. Therefore, kenaf fibre was chosen as partial replacement material to be reinforced with Glass/epoxy composite to reduce the weight and bulkiness of the composite structures. This study used Epoxy as matrix and kenaf/glass fibres to reinforce fillers to fabricate the composites in various stacking sequences. Finite Element Analysis (FEA) was carried out using LS-DYNA software to investigate the tensile properties of the hybrid composite. The results showed a significant improvement in tensile values of the modelled composite exhibited by the kenaf/glass fibre. The tensile strength of the hybrid composites was comparable with the Glass/Kenaf/Epoxy hybrid composites’ experimental results. About 200% tensile strength improvement can be observed for both experimental and numerical for G/K/G/E sample than pure epoxy samples, thus making the new composite a potential substitute for insulator applications.

The present work focuses on investigating the effect of lattice geometry on compression behavior, deformation mechanism and energy absorption capability of 3D printed polymeric micro-lattice structures. The mechanical characteristics of lattice cores comprising of periodic body centered cubic (BCC) architecture unit-cells, printed with projection micro-stereolithography (PμSL) based 3D printing technique were experimentally and numerically examined. For a fixed mass and corresponding relative density of lattice, five variants of BCC lattice structures were built by varying unit cell size, numbers and its strut diameter. The quasi-static compression tests were performed to determine the load-displacement history, stress-strain curves and deformation modes of lattice structures. The experimental results show that number of unit cells with in a certain volume of lattice block can have significant effect on compression properties of lattice structure. Within the same geometric envelop and mass properties, the lattice containing higher number of cells with reduced strut diameter tends absorb more energy as compared to a lattice with fewer number of cells with increased strut diameter. The elastic modulus, collapse and plateau stresses of lattice increase while densification strain decreases with the increase in number of unit cells. Moreover, there exists a certain number of cells in certain volume of lattice structure for which the energy absorption is higher, after that number the effect not significant. The deformation behavior of lattice was inspected and bending dominant deformation modes were observed in all lattice structures. The lattice with small cells shows progressive layer by layer collapse while for larger cell sized lattice show signs of buckling effect with central localized deformation modes. Lastly, the experimental outcomes were numerically implemented in finite element (FE) solver LS-DYNA to model the compression process, collapse behavior and deformation modes of lattice blocks. The compression characteristics and collapse modes predicted by FE model were in good agreement with experimental findings.

In recent years, vehicle demographics have changed to include a relatively large proportion of light trucks, such as pickups, vans and sport-utility vehicles. It is found that several types of guardrail systems, including the G4(2W) guardrail system, are unable to redirect the pickup trucks to roadway safely. Therefore, in this study, several options are considered; they include improving the splice connections and adjusting the guardrail height and the post spacing to improve the performance of this system. The G4(2W) guardrail system is modelled in LS-DYNA and validated with a previous full-scale crash test conducted by the Texas A&M Transportation Institute. A parametric study based on the results of the LS-DYNA crash simulation according to Length of Need test 3-11 and 3-10 is conducted to investigate key factors of guardrail systems, including the splice configuration, the post spacing and the guardrail height. The purpose of this study is to find a model that satisfies the requirements of Test Level 3 outlined in Manual for Assessing Safety Hardware (MASH)'s criteria.

In the initial phase of the research work, quasistatic compression tests were conducted on the expanded polystyrene (EPS) crushable foam for material characterisation at low strain rates (8.3×10-3~8.3×10-2 s−1) to obtain the stress strain curves. The resulting stress strain curves are compared well with the ones found in the literature. Numerical analysis of compression tests was carried out to validate them against experimental results. Additionally gravity-driven drop tests were carried out using a long rod projectile with semispherical end that penetrated into the EPS foam block. Long rod projectile drop tests were simulated in LS-DYNA by using suggested parameter enhancements that were able to compute the material damage and failure response precisely. The material parameters adjustment for successful modelling has been reported.

An important concern in metal forming is whether the desired deformation can be accomplished without defects in the final product. Various ductile fracture criteria have been developed and experimentally verified for a limited number of cases of metal forming processes. These criteria are highly dependent on the geometry of the workpiece and cannot be utilized for complicated shapes without experimental verification. However, experimental work is a resource hungry process. This paper proposes the ability of finite element analysis (FEA) software such as LS-DYNA to pinpoint the crack-like flaws in bulk metal forming products. Two different approaches named as arbitrary Lagrangian-Eulerian (ALE) and smooth particle hydrodynamics (SPH) formulations were adopted. The results of the simulations agree well with the experimental work and a comparison between the two formulations has been carried out. Both approximation methods successfully predicted the flow of workpiece material (plastic deformation). However ALE method was able to pinpoint the location of the flaws.