Abstract: Cellbond and ARUP have launched their advanced crash barrier models in 2006 and since the time a continuous study has been carried out to explore costumer requirements and review feedbacks. Existing barrier models are constructed using Solid element configuration in honeycomb segments along with validated Modified_Honeycomb material cards. Due to a number of demands on using Shell based honeycomb model in crash barriers by car manufacturers, it was decided to investigate the application in detail using full-scale test data. This paper represents the methodology of creating the Shell-based ODB and the comparison with existing solid based FE model. Frontal Offset tests are carried out by a large number of test houses worldwide, according to the European regulation and to FMVSS, as well as by EuroNCAP, Australian NCAP, JNCAP and IIHS. In the frontal offset test, only one side of a vehicles front end hits the deformable barrier, which means that a more concentrated area of the vehicles structure must sustain the impact of the crash rather than the whole width of the vehicle. The Cellbond ODB barrier has been investigated which consists of two different sized aluminium honeycomb blocks in main body and bumper partially covered in aluminium skins. Number of static compressive tests performed to specify honeycomb and adhesive material characters. The barrier was subjected to four individual test conditions with different impactor and impact speeds. (Download)

Abstract: Cellbond and ARUP have launched their advanced crash barrier models in 2006 and since the time a continuous study has been carried out to explore costumer requirements and review feedbacks. Existing barrier models are constructed using Solid element configuration in honeycomb segments along with validated Modified_Honeycomb material cards. Due to a number of demands on using Shell based honeycomb model in crash barriers by car manufacturers, it was decided to investigate the application in detail using full-scale test data. This paper represents the methodology of creating the Shell-based ODB and the comparison with existing solid based FE model. Show All

Abstract: The Offset Deformable Barrier (ODB) has been used by Euro NCAP and most of leading car manufacturers worldwide. This deformable barrier is used for frontal offset impact while the specifications developed by EEVC WG11. This paper represents the methodology to create the advanced Finite Element model of Cellbond's ODB barrier and certification through experimental test data. LS-DYNA was used to analyze the FE model and a number of static compressive tests performed at different angles to construct aluminum honeycomb Material Cards. The strain-rate scale factor curves are also defined to simulate the dynamic stiffening in the aluminium honeycomb during the analysis. Adhesive properties are obtained using Climbing Drum, T-Peel, Tensile and Plate Shear test results. The initial component tests generated a good correlation with FE outputs and to validate the barrier model, similar impact tests were performed in LS-DYNA environment respecting to four. In all assessments, the barriers were mounted on a rigid wall and were tested at certain impactor speeds. The Final comparison on overall results represents a good correlation between test data and CAE results for all tests. (Download)

Abstract: The Offset Deformable Barrier (ODB) has been used by Euro NCAP and most of leading car manufacturers worldwide. This deformable barrier is used for frontal offset impact while the specifications developed by EEVC WG11. This paper represents the methodology to create the advanced Finite Element model of Cellbond's ODB barrier and certification through experimental test data. Show All

Abstract: The US Federal Standard for Side Impact Protection (FMVSS 214) uses a deformable barrier and defines the dimensions and materials of the barrier, as well as the crush strength of the aluminium honeycomb parts in the main block and the bumper. This deformable barrier is also used for rear impact according to the updated FMVSS 301. This paper represents the methodology to create the advanced Finite Element model of Cellbond's NHTSA barrier and validation through experimental test data. The explicit LS-DYNA was used to analyze the model while number of static compressive tests performed at different angles to characterize aluminum honeycomb Material Cards. A strain-rate scale factor curve is defined to simulate the dynamic stiffening in the aluminium honeycomb during the analysis. Adhesive properties are also obtained using Climbing Drum, T-Peel, Tensile and Plate Shear test results. The preliminary component tests generated a good correlation with FE outputs and to validate the barrier model, similar impact tests were performed in LS-DYNA environment respecting to three experiments Flat-Wall, Rigid-Pole and Rear-Armature tests. In all assessments, the barriers were mounted on a moving trolley and were tested at certain speeds. The Final comparison on overall results represents a good correlation between test data and CAE results for all tests. (Download)

Abstract: The US Federal Standard for Side Impact Protection (FMVSS 214) uses a deformable barrier and defines the dimensions and materials of the barrier, as well as the crush strength of the aluminium honeycomb parts in the main block and the bumper. Show All

Abstract: The IIHS (Insurance Institute for Highway Safety) MDB was developed by Cellbond in 2001 in conjunction with the institute. This barrier is used by the IIHS in their side impact tests and the shape is designed to represent the front end geometry of a typical SUV or pickup. The impactor consists of two different sized aluminium honeycomb blocks partially covered in aluminium sheets. This barrier has been investigated to produce an advanced FE model while experimental Flat-Wall and Solid-Pole test results are used to evaluate accuracy of developed model. The explicit LS Dyna 3D was used to analyze the model, and validated against number of static compressive tests performed at different angles to characterize Yielding aluminum honeycomb parts and corresponding Material Card data. A strain-rate scale factor curve is also defined to convert static test results into suitable data in honeycomb material card during the analysis procedure. Adhesive properties are obtained using Climbing Drum, T-Peel, Tensile and Plate Shear test results. The dynamic analysis was validated by a Flat-Wall test which represents the crush performance of IIHS barrier. This was mounted on a moving trolley that was tested at speed of 25 Km/h. In Pole test, the IIHS barrier is subjected to a symmetric crush with a rigid vertical pole in which test speed is 25 Km/h. The Final comparison on overall results represents a good correlation between test data and CAE results on both Flat-Wall and Pole tests. (Download)

Abstract: The IIHS (Insurance Institute for Highway Safety) MDB was developed by Cellbond in 2001 in conjunction with the institute. This barrier is used by the IIHS in their side impact tests and the shape is designed to represent the front end geometry of a typical SUV or pickup. Show All

Abstract: This paper represents a new Finite Element simulation model for AE-MDB v3.9 side impact barrier and proposes a method on creating suitable assumptions and material data. Cellbond AE-MDB barrier investigation was carried out to produce an advanced FE model. Experimental Flat Wall and Offset Pole test results were used to validate the accuracy of the developed models. The explicit LS Dyna 3D code was used to model the geometries, and the Material Card data was obtained from several static compressive tests at different angles to characterize the yielding function of the aluminum honeycomb parts. The dynamic models were also validated by a Flat Wall test which represents the crash performance of AEMDB barrier. For dynamic tests the barrier was mounted on a mobile trolley and it was tested at speed of 35 km/h . In Offset Pole test, the AE-MDB barrier was subjected to an asymmetric crush with a rigid vertical pole in which test speed was 20 km/h. The final comparison of the overall results demonstrates a good correlation between test data and CAE results for both the Flat Wall and Offset Pole tests.(Download)

Abstract: This paper represents a new Finite Element simulation model for AE-MDB v3.9 side impact barrier and proposes a method on creating suitable assumptions and material data. Cellbond AE-MDB barrier investigation was carried out to produce an advanced FE model. Show All

Abstract: This paper represents a Finite Element model of Cellbond's aluminium honeycomb sandwich panel and proposes an original technique to develop the material characteristics which realistically simulate a child headform impacting on a sandwich panel. As part of a major study to develop a pedestrian friendly car bonnet design, this investigation has been carried out with the requirement as detailed in the EEVC regulations. Thus, all specimens have been impacted at specific angle and test speed using pedestrian head impactors. The Finite Element solution is based on the numerical simulation using the explicit FEA code DYNA3D, therefore, several preliminary tests were carried out to characterise the composite panel (honeycomb and adhesive) material properties used in the FE models. Results from preliminary component tests were used to describe the Modified-Honeycomb and Adhesive material cards. The final comparison of results from the experimental and numerical investigation represents a good correlation for the child impactor. (Download)

Abstract: This paper represents a Finite Element model of Cellbond's aluminium honeycomb sandwich panel and proposes an original technique to develop the material characteristics which realistically simulate a child headform impacting on a sandwich panel. Show All

Abstract: Although to have an accurate result of Finite Element analysis of a system is always enviable, on most of engineering problems it is worthwhile to find simpler models with less required time to solve and acceptable degree of accuracy those keep the general characteristics of system. Available numerical methods, however consider effect of different characters like air drainage and adhesive influence on crash behavior of honeycomb, but usually these assumptions are not applicable on big models especially when a complicated geometry is appraised. This paper validates a simple Finite Element model for honeycomb witch has an acceptable accuracy in crash analysis and is easily applicable on intricate problems. This model is desirable not only for simple honeycomb systems but also for sophisticated samples such as multi-layer or multimaterial honeycomb based structures. A comparison with experimental results shows good rate of exactitude for new simulation. (Download)

Abstract: Although to have an accurate result of Finite Element analysis of a system is always enviable, on most of engineering problems it is worthwhile to find simpler models with less required time to solve and acceptable degree of accuracy those keep the general characteristics of system. Show All

Abstract: Of all pedestrian fatalities, head injuries are the most common cause. [3,4] and in response organisations, and bodies across Europe and Japan have developed subsystem testing based on head-form into bonnet testing.

In turn, this has lead to the specification and development of a range of child and adult pedestrian head-form impactors, related certification methods and criteria.

The requirement is for highly standardised, and repeatable impactors for use in sub-system testing. Although, a range of parameters exists to define head-forms, there are a nonetheless factors and variances which may influence the suitability of an impactor. This is particularly relevant given that different manufacturers exist. In addition a number of studies exist focussing on the use of the bio-fidelity drop certification method, but there is a shortfall investigating the effectiveness, and repeatability of the EEVC lateral certification technique.

The present study investigated the repeatability of the lateral certification technique, and compatibility of different manufacturers (Jasti and an alternative) using an EU adult (4.8kg head-form). The results showed a lower repeatability for the lateral certification technique, compared to the bio-fidelity drop certification method, but still afforded a sufficient level of repeatability. The head-forms showed almost ideal response near the centre of the certification corridor, and generally high levels of repeatability, regardless of the manufacturer. These findings extended to the use of "mixed" head-forms i.e. using a core from one manufacturer and a skin from another. As such it appears acceptable to use "mixed" head-forms for sub-system testing. (Download)

Abstract: Of all pedestrian fatalities, head injuries are the most common cause. [3,4] and in response organisations, and bodies across Europe and Japan have developed subsystem testing based on head-form into bonnet testing. Show All

Cellbond Composites Ltd. is currently working on a new front bumper design, which meets the conflicting requirements for pedestrian protection and low speed collisions.

For speeds below 5 mph, the bumper stiffness should be high, while for higher speeds the bumper must have a low stiffness and good energy absorption characteristics. Monitoring vehicle speed so the bumper stiffness can be adapted accordingly is the key principle behind this concept.

The innovative element of this adaptive system concerns the anisotropic material (e.g. honeycomb) situated behind the bumpers front face. By rotating this component through a range of angles, a number of stiffness levels can be realised.

Cellbond Composites Ltd. is currently working on a new front bumper design, which meets the conflicting requirements for pedestrian protection and low speed collisions. Show All

Safety is becoming an increasingly important subject for car manufacturers. This is due to legislators in the form of regulations such as FMVSS 201, 208, 214 for occupant protection, and recent proposals from working group 17 to the European Commission. Public awareness is also increasing through programmes such as EuroNCAP. The industry is increasingly using its products' safety features as a marketing tool.

To meet the present and increasing demand for enhanced safety in cars, the ideal energy absorber should work as a multi-functional element. It should also function as a structural component, a heat exchanger, an air filter, a liquid-storage component, or as an acoustic insulator. Other important considerations are the ability to recycle the component and minimise its weight.

The ability of the absorber to give consistent results under various impact angles, its ease of manufacture, its performance under various environmental conditions and its ease of handling will all be of concern to the designer. Ease of modelling will also be required for accurate implementation of the countermeasure.

Sandwich structures can offer designers many of the above benefits. Traditionally, these were made from foams and honeycomb materials. In this paper, the PressLoad material is investigated in detail under a range of conditions, and we will be examining its performance relative to other commonly available materials, giving practical examples of how to apply it to critical locations within the car.

In addition, we will be discussing its use both as a primary component and as an add-on.

Safety is becoming an increasingly important subject for car manufacturers. This is due to legislators in the form of regulations such as FMVSS 201, 208, 214 for occupant protection, and recent proposals from working group 17 to the European Commission. Show All