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Three-point bending under quasi-static loading was carried out on empty and partially foam-filled tubes. ALPORAS® aluminum foam was used as an insert with aluminum alloy tube in the experiment. The experiment was modeled using the finite element (FE) code software package LS-DYNA®. The Deshpande-Fleck constitutive model was implemented in the simulation to model the foam. Its material parameters were calibrated against experimental data. The material parameters for the tube were also derived experimentally. Experimental data showed increase in specific energy absorption of approximately 17% whilst the lowest generator of the tube was found to increase by approximately 14% with inclusion of partially filling foam. The FE simulations compared well with the experiments, with the load-displacement and LG-indenter displacement agreeing within approximately 15%. Visual inspection of the foam showed local densification around the point of indentation.

This paper presents a methodology for simulating Fluid Structure Interaction (FSI) for a typical vehicle bonnet (hood) under a range of onset flow conditions. The hood was chosen for this study, as it is one of the panels most prone to vibration; particularly given the trend to make vehicle panels lighter. Among the worst-case scenarios for inducing vibration is a panel being subjected to turbulent flow from vehicle wakes, and the sudden peak loads caused by emerging from a vehicle wake. This last case is typical of a passing manoeuvre, with the vehicle suddenly transitioning from being immersed in the wake of the leading vehicle, to being fully exposed to the free-stream flow. The transient flowfield was simulated for a range of onset flow conditions that could potentially be experienced on the open road, which may cause substantial vibration of susceptible vehicle panels.

At higher speeds aerodynamic noise tends to dominate the overall noise inside the passenger compartment. Large-scale turbulent conditions experienced on the road can generate different noise characteristics from those under steady-state conditions experienced in an acoustic wind tunnel. The objective of this research is to assess the relationship between on-road flow conditions and the sound pressure level in the cabin. This research, covering links between the unsteady airflow around the vehicle and aeroacoustic effects, is a natural progression from previous aerodynamic studies. On-road testing was undertaken using a current production vehicle equipped with a mobile data logging system. Testing was carried out on major roads at typical highway speeds, where wind noise is very significant. Of particular interest are high-yaw conditions, which can lead to a blustering phenomenon.

The increased application of lightweight materials, such as aluminium has initiated many investigations into new joining techniques for aluminium alloys. As a result, Self-piercing riveting (SPR) was introduced into the automotive industry as the major production process to join aluminium sheet body structures. Although both hydraulic and servo types of SPR equipment are used by the industry, the servo type is most commonly used in a volume production environment. This type uses stored rotational inertia to set the rivet. The initial rotational velocity of the mass dictates the setting force and hence the tool is described as velocity-controlled. A study was therefore conducted to examine the effect of setting velocity on the process including tooling and joint performance. It was found that the setting velocity would have a significant effect on tooling life. Over 80kN force could be introduced into the tooling depending on selection of the setting velocity.

Vehicle wind noise is becoming increasingly important to customer satisfaction. Early wind noise assessment is critical to get things right during the early design phase. In this paper, SEA modeling technique is used to predict vehicle interior noise caused by the exterior turbulence. Measured surface turbulence pressures over vehicle greenhouse panels are applied as wind noise load. SEA representation of wind noise load case is investigated. It has been found that current SEA wind noise load case over-estimates at frequencies below window glass coincident frequency. A new concept of noise source pole index is introduced and a new wind noise load coupling has been developed. Comparison with vehicle wind tunnel measurements shows that the proposed load case significantly improved prediction accuracy.

Simulation of local flow structures in the A-pillar/side glass region of bluff SUV geometries, typical of Land Rover vehicles, presents a considerable challenge. Features such as relatively tight A-pillar radii and upright windscreens produce flows that are difficult to simulate. However, the usefulness of aerodynamics simulations in the early assessment of wind noise depends particularly on the local accuracy obtained in this region. This paper extends work previously published by the author(1) with additional data and analysis. An extended review of the relevant published literature is also provided. Then the degree to which a commercial Lattice-Boltzman solver (Exa PowerFLOW™) is currently able to capture both the local flow structure and surface pressure distribution (both time averaged and unsteady) is evaluated. Influential factors in the simulation are shown to be spatial resolution, turbulence and boundary layer modelling.

The sand-water erosion behaviour of notched holes in glass/epoxy composites was investigated. Using tnrough-the-thickness stitching, the amount of hole damage caused by impact testing prior to wear tests was varied. Erosion resistance was evaluated based on the amount of mass loss. Results showed that the holes in unstitched laminate which incurred greatest impact damage, eroded the least. The holes in stitched laminates, however, were more susceptible to erosive wear even though the internal damage appeared less severe. SEM photographs showed that the lower half of the holes in the unstitched laminates remained intact while those in the stitched laminates were eroded substantially. Cut sections away from the hole were observed with an optical microscope. A comparison of cut sections showed that heavy stitching results in severe fibre impalement damage, thereby reducing the reinforcing capability of the fibres around the hole.

The paper presents the development of delamination resistant composite laminates using interleaving technology. A simple technique which incorporates discrete layers of thin thermoplastic films between wet glass/epoxy prepreg, followed by co-curing, is described. Two types of films having widely different properties were used in order to investigate the effects of film characteristics on composite interlaminar shear strength. Microscopic observations of the specimens after four-point shear testing showed that the failure mode was strongly affected by both the presence and the characteristics of the interleaves.

Aluminium-lithium (Al-Li) alloys have gained prominence in the aerospace industry in recent years as structural materials. This is due primarily to their mechanical properties, such as high specific strength and modulus, and low density. Development of Al-Li/ceramic composites is currently being investigated to enhance the higher service capabilities of this material. Processing of Al-Li/ceramic composites by the powder metallurgy (PM) route offers many advantages over ingot casting such as a well-dispersed reinforcement distribution and easy handling. However, the PM route suffers from agglomeration of the ceramic reinforcement when the particle size is below 2.5 μm. This paper reports the development of several methods of mixing submicron ceramic powders with Al-Li to obtain a uniform distribution of the reinforcement. Among the methods used were mixing in a fluidized bed, ball milling, spray drying and mixing the metal powder with a ceramic slurry.