Load Pin Segmented Relief Surfaces for Strain Uniformity
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Solution Overview
Problem
Many load pins lack sufficient stiffness and uniformity in their ends, leading to non-uniform loading behavior under tensile and compressive loads, which complicates precision measurement and results in varying strain gage outputs.
Innovation Solution
A load pin design featuring a main body with distinct loading and relief surfaces, recesses, sensor pockets, and wiring channels, which provides improved structural integrity and consistent strain measurement across both tensile and compressive loads by optimizing the placement and connectivity of strain gages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional load pin design is used, then manufacturing is simpler, but measurement precision deteriorates due to non-uniform loading behavior
Solution Approach 1:
The load pin is segmented into distinct functional zones: loading surfaces for force application, relief surfaces for stress relief, and a sensing portion with strain gages. This segmentation allows each zone to perform its specific function optimally, ensuring uniform loading at the sensing portion while maintaining manufacturing feasibility through standardized features.
Solution Approach 2:
Different regions of the load pin are given different geometric properties: the loading surfaces have specific diameters and orientations optimized for force application, the relief surfaces have reduced diameters for stress management, and the sensing portion has precise dimensions for accurate strain measurement. This local optimization of geometric quality improves measurement precision without requiring complete redesign of the entire pin.
2Measurement precision
If load pin has stiff isolated ends, then measurement precision improves, but manufacturing complexity increases
Solution Approach 1:
The load pin design incorporates pre-formed loading surfaces and relief surfaces during manufacturing, establishing the stiff isolated ends and uniform loading zones before the pin is installed. This preliminary structuring ensures measurement precision is built into the component itself, while the manufacturing processes (machining, forming) remain conventional and manageable.
3Adaptability or versatility
If load pin exhibits non-uniform loading, then tensile and compressive behavior varies, but strain gage output consistency deteriorates
Solution Approach 1:
The load pin employs asymmetric loading surfaces and relief surfaces with specific diameter relationships (loading surface diameter greater than relief surface diameter) to create uniform stress distribution at the sensing portion. This asymmetric geometry ensures that both tensile and compressive loads produce consistent, uniform loading at the strain gage location, improving output consistency across different loading conditions.
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 design enhances sensitivity and linearity of load measurements under both tensile and compressive loads, reducing the difference in strain responses and providing more accurate and consistent output.
Implementation Method 1
The strain gages are configured to measure loads in the load pin and to generate a signal proportional to the measured load
Data Source
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AI summary
A load pin includes a main body, a plurality of recesses, and a plurality of sensor pockets. The main body has a plurality of loading surfaces and a plurality of relief surfaces formed therein. Each loading surface is disposed between two of the relief surfaces. The recesses are formed in and extend at least partially around the outer surface of the main body. Each recess has a substantially round inner surface, is formed in a different one of the relief surfaces, and is disposed between a different pair of loading surface. The sensor pockets are formed in the outer surface, extend partially into the main body, are disposed between a pair of loading surfaces, and extend through the recess that is disposed between the same pair of loading surfaces.