Vehicle Inner Panel Bead Design for Head Impact Energy Absorption
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Solution Overview
Problem
Current hood structures for vehicles face challenges in achieving both a larger first acceleration wave for early energy absorption and a smaller second acceleration wave due to limited space, necessitating a design that enhances stress propagation and reduces local deformation during head impacts while allowing easy crushing upon contact with built-in components.
Innovation Solution
An inner panel design featuring upward convex and downward convex beads with an inverted U and U shape respectively, arranged alternately, and a bead forming surface positioned between them to promote bending deformation and reduce deformation resistance, enhancing stress propagation and energy absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If U-shaped beads are provided to increase flexural rigidity and first acceleration wave, then pedestrian protection is improved, but the clearance between hood panel and built-in components becomes insufficient
Solution Approach 1:
The bead structure is segmented into upper and lower beads with different functions. Upper beads provide flexural rigidity for increasing first acceleration wave, while lower beads allow controlled deformation for maintaining clearance. This segmentation resolves the contradiction by distributing different protective functions to different structural elements.
Solution Approach 2:
Different regions of the hood panel are given different structural qualities through the bead configuration. The upper beads create rigid zones for energy absorption, while the lower beads create flexible zones for controlled deformation. This local differentiation allows simultaneous achievement of high first acceleration wave and sufficient clearance.
2Use of energy by moving object
If the first acceleration wave is enlarged to increase energy absorption, then the deformation stroke is reduced, but the structural complexity increases
Solution Approach 1:
The bead structures utilize curved geometries with specific radii of curvature to achieve controlled deformation characteristics. The curved profiles of upper and lower beads create progressive deformation zones that absorb energy efficiently while maintaining manufacturing feasibility through standard forming processes.
Solution Approach 2:
The bead dimensions, spacing, and curvature parameters are optimized to achieve target acceleration waveforms. By adjusting parameters such as bead height, width, and longitudinal spacing, the structure achieves desired energy absorption characteristics without requiring complex additional components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively increases the first acceleration wave for early energy absorption and reduces the second acceleration wave by promoting bending deformation and easy crushing, thereby improving pedestrian protection while maintaining structural integrity.
Implementation Method 1
promote bending deformation and easy crushing, thereby improving pedestrian protection
Implementation Method 2
it is necessary during a head impact to absorb the collision energy before the hood contacts built-in components
Data Source
AI summary
According to an inner panel for vehicles of the present invention, a bead forming surface is so provided as to extend continuously with an upper edge part of a wall rising from a bottom surface of the inner panel. Upper beads and lower beads are formed on the bead forming surface. The upper and lower beads extend in a longitudinal direction of a vehicle and are arranged alternately in a width direction of the vehicle. The bead forming surface is positioned above a middle position between an upper surface of the upper bead and a lower surface of the lower bead. Further, the bead forming surface is positioned lower than the upper surface of the upper bead by 3 mm or more. With this structure, a sufficient first acceleration wave can be secured by expanding a stress propagation range in a direction perpendicular to the length of the beads with respect to the first acceleration wave and, also, by reducing a local deformation to be caused by a deformation load from the above of the vehicle during a head impact. Further, with respect to a load from below of the vehicle when contacting built-in components, the inner panel is easily crushed, which can lower a second acceleration wave.