Passenger Car Side Sill Joint for Small-Overlap Crash Loads
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Solution Overview
Problem
Existing passenger car bodies face structural integrity issues during frontal impacts, particularly with small width overlap, due to high loads on joining joints in the rear wheel region leading to potential failure of connection points.
Innovation Solution
A form-fitting connection between the side sill and a side member, with a protrusion engaging in a recess, is combined with additional integrally bonded and frictionally engaged joining systems, and a gap filled with structural foam to enhance structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a joining system is used to connect the side sill and side member, then the structural integrity is improved, but the risk of connection failure under high impact load increases
Solution Approach 1:
The connection system is divided into multiple independent load-bearing elements: a form-fit connection with protrusion and recess, multiple screw connections, and adhesive bonding. This segmentation distributes the impact load across multiple connection points rather than relying on a single joining system, preventing connection failure under high impact loads during frontal collisions.
Solution Approach 2:
The connection system combines multiple connection methods (mechanical screw connections, chemical adhesive bonding, and geometric form-fit connection) to create a composite connection system. This multi-mode connection approach provides redundant load paths and ensures structural integrity even when individual connection elements are overloaded during impact events.
2Reliability
If the side member is positioned further inwards than the side sill, then the accident behavior is improved, but the manufacturing complexity increases
Solution Approach 1:
The side member is positioned inwards within the space defined by the side sill, creating a nested arrangement where the side member occupies the interior space between the side sill and the vehicle floor. This nested configuration optimizes the accident behavior by positioning load-bearing elements strategically while managing the overall vehicle structure.
Solution Approach 2:
The form-fit connection features are pre-designed into the side member and side sill during the manufacturing process, with protrusions and recesses positioned to automatically engage when assembled. This preliminary design of the interlocking features simplifies the assembly process and ensures proper positioning of the side member relative to the side sill, reducing manufacturing complexity despite the inwards positioning requirement.
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 solution ensures a high structural integrity and improved accident behavior by distributing impact loads effectively, reducing the risk of connection failure during frontal crashes.
Implementation Method 1
a gap filled with structural foam to enhance structural integrity
Data Source
AI summary
A body of a passenger car includes a side sill and a side member in a region of a rear end of the body where the side member is disposed further inward in a transverse direction of the passenger car than the side sill. The side sill has a recess disposed in front of a rear wheel of the passenger car in a longitudinal direction of the passenger car. The side member has a protrusion which projects in the transverse direction of the passenger car. The recess is engaged by the protrusion. A structural foam is disposed in a gap that is disposed in the longitudinal direction of the passenger car between the protrusion and a wall of the side sill which delimits the recess in the longitudinal direction of the passenger car such that the protrusion is supported on the wall in the longitudinal direction of the passenger car.