Vehicle Side Sill Structure for Offset Collision Impact
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Solution Overview
Problem
Conventional side body structures for vehicles experience excessive deformation and weight when subjected to narrow offset collisions due to the movement of impact loads along the side sill, leading to inefficient impact absorption.
Innovation Solution
A side body structure featuring a side sill with a closed cross-sectional shape, comprising separate upper and lower inner members with varying tensile strengths, a reinforcing member, and a hat-shaped cross-section design, which allows for controlled deformation and load distribution during collisions, using high-tensile steel and strategic welding to enhance strength and reduce weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the side sill inner is separated into two parts with the upper part having greater thickness, then the impact absorption capability is improved, but the weight of the vehicle increases
Solution Approach 1:
The side sill inner members are designed with non-uniform thickness distribution, where the upper inner member has greater thickness than the lower inner member. This local quality variation concentrates material where impact forces are most intense (upper region), providing enhanced impact absorption capability while minimizing unnecessary material in lower regions, thus reducing overall weight compared to uniform thickness designs.
2Ease of manufacture
If the side sill is designed with integrated structure, then the manufacturing simplicity is improved, but the impact absorption efficiency in narrow offset collisions deteriorates
Solution Approach 1:
The side sill inner is divided into separate upper and lower inner members that can be manufactured independently and then assembled together using reinforcing members. This segmentation allows each member to be optimized for its specific functional requirements - the upper inner member for impact absorption and the lower inner member for structural support - while enabling more efficient impact load distribution during narrow offset collisions compared to integrated designs.
3Strength
If the upper inner member has higher tensile strength material, then the load bearing capacity is improved, but the manufacturing complexity increases
Solution Approach 1:
High-tensile-strength material is selectively applied only to the upper inner member where impact loads are most intense, rather than using expensive high-strength material throughout the entire side sill structure. The lower inner member can use standard strength material since it experiences lower stresses. This localized material selection optimizes load bearing capacity at critical locations while minimizing overall manufacturing cost and complexity.
4Strength
If the side sill uses thicker material throughout, then the strength is improved, but the weight increases
Solution Approach 1:
The side sill structure employs variable thickness design where the upper inner member has greater thickness than the lower inner member. This local quality variation provides enhanced strength and impact absorption capability where needed (upper region experiencing higher impact forces) while using thinner, lighter material in lower regions where stresses are reduced, achieving optimal strength-to-weight ratio compared to uniform thickness designs.
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
The structure effectively absorbs impact loads by deforming the front portion of the side sill, reducing deformation and weight while maintaining strength, and allowing for efficient load transfer and absorption during narrow offset collisions.
Implementation Method 1
a deforming portion of the side sill is defined ahead of the reinforcing member, the deforming portion is to be deformed by a load applied in a longitudinal direction of the side sill
Implementation Method 2
when a collision (narrow offset collision) occurs at the front, for example, at the left end of the front of the vehicle and a load is applied thereto, a deforming portion disposed at the front of the side sill is deformed upward
Implementation Method 3
The upper inner member is formed by a hot-press and the lower inner member is formed by a cold-press
Implementation Method 4
The upper inner member is formed by a hot-press and the lower inner member is formed by a cold-press
Data Source
AI summary
A side body structure for a vehicle includes a side sill. The side sill includes a closed cross sectional shape which is formed by a side sill inner and a side sill outer, the side sill inner includes an upper inner member and a lower inner member which are separate members, a tensile strength of the upper inner member being higher than a tensile strength of the lower inner member, the side sill has. At a front portion of the side sill, a deforming portion which is to be deformed by a load applied in a longitudinal direction of the side sill is provided. The upper inner member and the lower inner member are connected together by a reinforcing member which is disposed close to the deforming portion and in the closed cross section.