Segmented Crash Cushion Posts Prevent Vehicle Lifting
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Solution Overview
Problem
Post-type crash cushions face inefficiency due to vehicles lifting and potentially rolling over when hitting inclined posts, reducing the effectiveness of subsequent post deformation and energy absorption.
Innovation Solution
The design features posts with a sloping upper section that prevents vehicle lifting by ensuring consistent impact height and force distribution across all posts, connected by rectangular bases or directly driven into the ground, with optional horizontal retaining crossbars for stability and impact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If posts are inclined to absorb energy through bending, then energy absorption capability is improved, but vehicle lifting occurs reducing effectiveness of subsequent posts
Solution Approach 1:
The post is divided into two distinct sections: an upper inclined section for energy absorption and a lower vertical section for maintaining impact height. This segmentation allows each section to perform its specific function independently, resolving the contradiction between energy absorption and preventing vehicle lifting.
Solution Approach 2:
Different sections of the post have different geometric properties - the upper section is inclined at angle α to maximize energy absorption, while the lower section is vertical to maintain consistent impact height. This local differentiation of properties allows the post to simultaneously achieve both energy absorption and prevent vehicle lifting.
2Loss of energy
If posts are made taller to increase energy absorption, then energy absorption is improved, but device complexity and installation difficulty increase
Solution Approach 1:
The post is segmented into upper and lower sections with different functions, allowing the upper section to be optimized for energy absorption while the lower section maintains a simple vertical structure for easy installation and consistent performance.
Solution Approach 2:
The inclination angle α of the upper section is optimized to provide effective energy absorption, while the lower section maintains a fixed vertical orientation. This parameter differentiation allows the post to achieve high energy absorption without increasing overall complexity.
3Reliability
If posts are connected by chains to prevent free movement, then vehicle stopping capability is improved, but device complexity increases
Solution Approach 1:
Instead of using chains to connect posts and prevent movement, the invention inverts the approach by making each post self-stabilizing through its lower vertical section that maintains consistent impact height and orientation, eliminating the need for inter-post connections.
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 stops vehicles without lifting, maintaining consistent energy absorption and force distribution, ensuring optimal operation and safety by preventing rollovers and allowing for flexible installation near obstacles like trees.
Implementation Method 1
The crash cushion absorbs the kinetic energy of the hitting vehicle due to deformation of the posts, which are subjected to bending
Implementation Method 2
the vehicle drives under the upper section inclined forward, hitting it with the bonnet and/or bumper, causing it to hit the ground and not to lift
Data Source
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AI summary
The crash cushion, according to the invention, consists of at least one posts (1) divided into an upper section (1a) and a lower section (1b), where the upper section (1a) being straight, broken or curved, so that after the post (1) has been projected on a vertical plane (Vp) passing through the longitudinal axis (La) of the cushion, the angle between the upper section and lower section α is between 5° and 175°, the height of the lower section h is between 300 mm and 1200 mm, and the length of the upper section l is between 100 mm and 1000 mm.