Crash Test Dummy Pelvis With Buttock Cavity for Compression Simulation
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Solution Overview
Problem
Current anthropomorphic test devices fail to achieve proper buttock compression of the pelvis assembly, which is essential for simulating human-like response during collision testing, especially in reclined seating postures, due to inadequate material stiffness in existing designs.
Innovation Solution
The introduction of a pelvis member with a foam core and a buttock region that defines a separate cavity with at least one vent port, allowing the buttock cavity to compress from an open to a collapsed condition when a force is applied, simulating the weight of a human, thereby enhancing the human-like response during collision testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If different materials such as foams are used to soften the pelvis flesh stiffness, then the buttock compression is improved, but the mechanical impact response is insufficient to cause human-like interaction during collision testing
Solution Approach 1:
The pelvis member is segmented into multiple functional regions: a rigid structural core for mechanical impact response, a compressible foam layer for buttock compression, and a separate buttock cavity for simulating soft tissue deformation. This segmentation allows each region to independently perform its specific function without compromising the others.
Solution Approach 2:
The pelvis member employs a composite structure combining rigid materials (for structural integrity and impact response) with compliant foam materials (for buttock compression). This composite approach enables the pelvis to simultaneously exhibit both hard structural characteristics for collision testing and soft tissue characteristics for seating comfort simulation.
2Ease of operation
If low density foams are used to achieve proper buttock compression, then the compression softness is improved, but the pelvis assembly cannot maintain proper mechanical properties for collision testing
Solution Approach 1:
Different regions of the pelvis member are assigned different material properties: the structural core uses rigid materials for mechanical strength, while the buttock region uses soft foam for compression. This local differentiation of material quality allows the pelvis to be soft where needed for comfort simulation while maintaining overall structural integrity for collision testing.
Solution Approach 2:
The pelvis member is divided into distinct functional segments with independent material properties. The rigid structural core provides mechanical strength, while the separate foam-filled buttock cavity provides localized softness for compression simulation, allowing simultaneous optimization of both contradictory requirements.
3Reliability
If the pelvis member is made rigid to maintain structural integrity, then the mechanical impact response is improved, but the buttock compression simulation is insufficient
Solution Approach 1:
The pelvis member is segmented into a rigid structural core for maintaining structural integrity and mechanical impact response, and a separate compliant buttock cavity filled with foam for simulating buttock compression. This segmentation allows the rigid core to provide reliable structural support while the soft foam cavity independently provides realistic compression simulation during seating.
Solution Approach 2:
The pelvis member combines rigid structural materials with compliant foam materials in a composite construction. The rigid portion maintains structural integrity for collision testing, while the foam portion provides the necessary compression characteristics for buttock simulation, resolving the contradiction between rigidity and softness.
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 replicates the human-like response by accurately compressing the buttock region, improving the simulation of seat height and kinematics, particularly in reclined seating positions, thus enhancing the realism of collision testing and aiding in the design of safer vehicles.
Implementation Method 1
The foam core and the skin portion define a buttock cavity that compresses from an open condition to a collapsed condition when the anthropomorphic test device is placed onto a surface
Implementation Method 2
The buttock region also defines at least one vent port
Data Source
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AI summary
An anthropomorphic test device includes a pelvis member. The pelvis member has a foam core and includes an abdomen region defining a first cavity and a pair of thigh regions extending from the abdomen region. The pelvis member also includes a buttock region positioned below the abdomen region and rearward of the pair of thigh regions. The buttock region defines a buttock cavity separate from the first cavity with the buttock region also defining at least one vent port. The buttock cavity compresses from an open condition to a collapsed condition when the anthropomorphic test device is placed onto a surface for approximating a force applied by a body weight of a human.