Vehicle Side Sill Support Structure Against Side-Collision Intrusion
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Solution Overview
Problem
In vehicles, particularly electric vehicles, the side sill structure is inadequate in preventing rotation and intrusion into the vehicle interior during side collisions, leading to increased occupant injury risk due to insufficient impact energy absorption and altered aerodynamic performance reducing ground clearance, causing higher impact points that damage the center pillar.
Innovation Solution
A side sill design incorporating a support member with a bent cross-section, bonded to the side sill outer part, which includes an upper surface, side surface, reinforcing portion, connection portion, and lower surface, providing additional stiffness and load path management through welding, and a multi-lip part with a concave portion to prevent rotation and intrusion during collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the side sill is lowered to improve aerodynamic performance, then electricity consumption efficiency is improved, but the impact point in side collision becomes higher causing center pillar damage and side sill rotation into vehicle interior
Solution Approach 1:
The side sill structure is divided into multiple components: side sill inner part, side sill outer part, and support member. This segmentation allows each component to perform specific functions - the outer part maintains aerodynamic profile while the inner structure and support member handle collision loads independently
Solution Approach 2:
The support member is configured with a bent cross-section having multiple portions (upper surface, side surface, reinforcing, connection, and lower surface portions) extending in different directions. This three-dimensional configuration creates multiple load paths and increases structural stiffness without increasing ground clearance
2Strength
If an aluminum extruding member is used to strengthen the side sill, then the side sill becomes more robust, but the cost increases significantly
Solution Approach 1:
Instead of using expensive aluminum extruding members throughout the entire side sill structure, the support member is strategically positioned and configured with a bent cross-section to provide localized reinforcement exactly where needed to prevent rotation and maintain structural integrity
Solution Approach 2:
The side sill structure combines different materials - the side sill inner and outer parts with the support member - to achieve the required strength and stiffness. This composite approach provides robustness comparable to aluminum extruding members while controlling manufacturing costs
3Strength
If a multi-lip structure is inserted into the side sill to increase robustness, then the side sill structure is strengthened, but the impact energy support capability remains insufficient
Solution Approach 1:
The support member is configured with a bent cross-section featuring curved surfaces instead of straight lines. This curved geometry provides superior structural efficiency, increasing moment of inertia and section modulus to enhance impact energy absorption and support capability
Solution Approach 2:
The support member extends in multiple dimensions with portions reaching toward the vehicle interior and exterior surfaces. This multi-dimensional configuration creates redundant load paths that effectively distribute and absorb impact energy from side collisions
4Ease of manufacture
If the side sill structure is simplified to reduce cost, then manufacturing cost decreases, but the side sill rotates and enters vehicle interior during side collision
Solution Approach 1:
The support member is pre-configured with a bent cross-section and strategically positioned within the side sill structure before collision occurs. This preliminary structural arrangement ensures that when side collision impact is applied, the support member is already in position to resist rotation and maintain structural stability
Solution Approach 2:
The support member's bent cross-section configuration changes the structural parameters of the side sill - increasing moment of inertia, section modulus, and overall stiffness. These parameter changes enhance rotational resistance and structural stability without requiring complex multi-component assemblies
Data Source
AI summary
A side sill for a vehicle including a side sill inner part and a side sill outer part having upper portions and lower portions bonded to each other. The side sill further includes a support member that is bonded to an inner surface of the side sill outer part and that is formed in cross section to be bent toward an inside of the vehicle at one or more places in a height direction of the vehicle.