Dual-Stage Bumper Energy Absorption for Pedestrian and Vehicle Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current motor vehicle bumper systems are impractical and often unable to meet diverse global regulatory requirements for both vehicle and pedestrian safety in low- and high-impact collisions with a single design, as they prioritize either energy absorption for the vehicle or the object struck.
Innovation Solution
A dual-stage energy absorption bumper system with 'softer' energy-absorbing surfaces at the front and 'rigid' surfaces at the rear, varying wall thickness, and materials with different stiffness properties, allowing for distinct energy absorption characteristics in low- and high-impact collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single bumper system is designed to meet all global regulatory requirements, then adaptability is improved, but device complexity increases due to conflicting requirements
Solution Approach 1:
The bumper system is divided into multiple energy absorption stages with different stiffness characteristics. The first stage has lower stiffness for pedestrian safety in low-impact collisions, while the second stage has higher stiffness for vehicle protection in high-impact collisions. This segmentation allows a single bumper system to meet conflicting regulatory requirements for different impact scenarios.
Solution Approach 2:
Different portions of the bumper system have different mechanical properties. The first energy absorbing stage uses materials and geometries optimized for pedestrian protection (softer, more compliant), while the second stage uses harder, more rigid materials and structures for vehicle protection. This local differentiation of material and structural properties enables the system to satisfy multiple regional safety standards simultaneously.
2Reliability
If energy absorption area is increased to meet multiple requirements, then energy absorption capability is improved, but ease of manufacture deteriorates due to styling constraints
Solution Approach 1:
The patent varies wall thickness, material stiffness, and geometric depth parameters across different sections of the bumper to create distinct energy absorption stages. By changing these physical parameters rather than simply increasing overall bumper size, the system achieves enhanced energy absorption capability while maintaining acceptable styling and manufacturability.
Solution Approach 2:
The bumper system employs composite construction with different materials or material configurations in different stages. The first stage may use softer, more compliant materials for pedestrian safety, while the second stage uses harder materials for structural protection. This composite approach enables differentiated energy absorption characteristics without requiring a uniformly large bumper design.
3Strength
If bumper design prioritizes vehicle protection in high-impact collisions, then strength is improved, but object-generated harmful factors increase due to lack of pedestrian protection
Solution Approach 1:
The bumper is segmented into two functional stages: a first stage with lower stiffness that deforms preferentially during low-impact collisions to protect pedestrians, and a second stage with higher stiffness that engages during high-impact collisions to protect the vehicle. This segmentation ensures that vehicle protection strength is maintained while minimizing harm to struck objects in appropriate scenarios.
Solution Approach 2:
The bumper system exhibits dynamic behavior where the stiffness and energy absorption characteristics change based on the impact force applied. During low-impact collisions, the softer first stage dominates the response to protect pedestrians. During high-impact collisions, the harder second stage becomes active to protect the vehicle. This dynamic response allows the system to adapt its protection characteristics to the severity of the collision.
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 dual-stage system effectively absorbs energy in low-impact collisions while providing adequate protection in high-impact scenarios, meeting various regulatory requirements and minimizing damage to both the vehicle and struck objects.
Implementation Method 1
a first energy absorbing stage having at least one first stage element having a first impact resistance
Implementation Method 2
a second energy absorbing stage having a second impact resistance; wherein the first impact resistance is less than the second impact resistance
Data Source
AI summary
A motor vehicle bumper that has enhanced energy absorption characteristics and that includes one or more unique geometry configurations that extend “softer” energy absorbing surfaces forward in the system while nesting more “rigid” energy absorbing surfaces more rearward only to come into effect when higher energy impacts are observed. The dual energy absorption may be achieved using a number of configurations and/or methods or a combination of several. In one or more embodiments, the wall thickness of the material used in the component or components may be varied, materials having different stiffness properties may be used, and/or geometries of different depth and section stiffness may be alternated across the bumper system.