Rectangular and round tubular structures are typically used in vehicles’ front structure to increase the energy absorption capacity in the event of an accident. There is significant interest in lighter structures for improving automobiles’ fuel efficiency with a challenge of maintaining or preferably exceeding the energy absorption properties of the structure. The structural members designed to take on the challenge of absorbing maximum amount of energy in a relatively short period of time while also maintaining reactive forces below damaging levels undergo progressive deformation under axial loading. The type of deformation mode is critical as it defines the overall configuration of force-displacement curve. There are different types of deformation modes for cross tube under axial loading. Likewise, cellular structure exhibit distinct deformation modes under in-plane loading. The work presented here investigates the effects of bonding of composite cellular core structure on deformation modes of cross tubes under axial loading. The numerical simulations were performed in ABAQUS finite element software. The cross tube was modeled as a deformable shell with edge lengths of 25.4 mm, wall thickness of 3 mm and an overall tube length of 160 mm. The cellular core was modeled to fill the cross-tube core and consisted of 40 rows and 7 columns of flattened honeycomb cells. The cellular core was partitioned into four sections of varying cell wall thickness and materials assigned were steel and 6 and 7 series aluminum alloys. Elastic-perfectly plastic material models were defined for both cross-tube and composite core structures. Fixed boundary conditions were applied to the bottom surface of the cross tube and cellular core and were attached to a fixed bottom plate. General contact properties were assigned to define interaction between the plates and the cross tube and core. Bonding between the core and tube walls was defined using tie constraints at discrete intervals. Tie constraint were defined by defining interaction between the inner surface of the cross tube and the perimeter of the discrete bonded zones.  Four cases were considered for analysis. The first case did not contain core bonding. The second case consisted of 3 bonding sites. In the third case, 5 bonding zones were defined and in the final case, 7 bonding sites were assigned. The results show that full, partial, or discrete bonding of composite cellular core with the tube has significant effect on progressive deformation of tubes and therefore, presents an opportunity to re-configure force-displacement curve for improved protection of automobile structures under impact loading.


Evaluation of Crushing Response of Limited Bonding of a Composite Core With a Cross Tube

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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