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CAD based interaction of wing structures and aerodynamic loads using finite element model and transonic small disturbance model

Zain R., Nurhadi I., Hadi B. H., Tjatra W.

Journal of KONES

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2013

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Vol. 20, No. 2

409--416

EN

A scheme has been developed to be utilized for solving the interaction between wing aerodynamic loads and the flexibility of wing structures under a quasi static assumption. The interaction is implemented through a link between the nodes of finite element model and the grids of transonic small disturbance model. The particular finite element responses, namely translational displacement vectors (TDV), are utilised for reconstructing the deflected wing surfaces. So in each iteration, the updated surfaces are involved as the parent for regenerating the TSD grids. The criteria of the Euclidean norm is applied for evaluating the convergency of aero-structure interaction. Catia-V5, is fully employed to manage three dimensional geometries for developing the model of wing structures, calculating grids and aerodynamic loads, as well as for reconstructing the updated wing surfaces. Numerous functions and objects of Catia are employed by conducting particular accesses via component object models using Microsoft Visual Basic.Net. A case study is excersized to demonstrate the interaction in transonic speed. The results shown that the scheme is very good in the way performing the interaction in quasi static condition. The utilization of TDV for generating the deflected wing surfaces indicates the capability of high fidelity deformations with respect to the complexity of finite element model.

2

Computer modelling of energy absorbing capability of bus superstructure for rollover safety

Nurhadi I., Zain R., Mihradi S., Soe Oo K.

Journal of KONES

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2011

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Vol. 18, No. 2

331-338

EN

This paper describes further investigations that have been carried out to make the proposed procedure [5] becomes more reliable to be practically applied as a requirement in bus type approval. One important aspect highlighted in this paper is an effort to improve the accuracy of the FEA model by taking into account detailed construction of bus superstructure. It worth to note that, based on survey carried out on several bus manufacturers, the detailed construction may vary from manufacturer to manufacturer. As a case study, a bus superstructure from a prominent manufacturer was chosen as a sample. Energy absorbing capacity of a bus superstructure section consisting of four bays including rear entrance door, emergency door and rear end was investigated through elastic-plastic finite element model. Incremental quasy static load according to ECE R66 was applied, subsequently to the right and left cantrail to obtain load deflection curve. Then the energy absorbing capacity of the structure when residual space limit was reached was evaluated through derived energy deflection curve. Essential components of the bus superstructure governing its energy absorbing capacity will be discussed. Modeling strategy in dealing with elastic-plastic analysis for such a rather complex structure is also highlighted.

3

Development of computer based procedure for quantitative evaluation of bus superstructure in type approval

Nurhadi I., Zain R.

Journal of KONES

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2010

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Vol. 17, No. 2

371-378

EN

This paper deals with development of a computer simulation procedure, as a substitute for physical rollover test, to evaluate bus body structure crashworthiness. It is expected that, when completed, this procedure can be proposed to the authority to enhance its current type approval procedure related to crashworthiness which is merely based on qualitative and empirical field experiences without performing real rollover test. This procedure will enable afirmer base for judging the crashworthiness of bus structure. The proposed computer simulation procedure is being developed based on ECE R66 which allows partial bus body structure to be physically tested. In this case, sections of bus super structure built up from at least two bays are used to represent the whole structure. A finite element method computer program capable of dealing with elastic plastic calculation is employed to calculate deflection of a bay structure under incremental quasi-static loading until residual space limit is reached. From the obtained force-deflection curve, the strain energy absorption capacity of the structure will be evaluated if it is large enough to absorb potential energy resulting from rollover test. A bus body superstructure sample from a representative domestic bus manufacturer is used as test cases.