HTS Wire Connection Structure Reducing Stress Concentration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-temperature superconducting coils made from multi-layer wire pieces face challenges in maintaining stress resistance and current density due to connection methods, which can lead to thermal runaway and reduced functionality when the superconducting layer is damaged.
Innovation Solution
A connection structure where the outer periphery of the tape-type laminated body, including a substrate and a high-temperature superconducting layer, is covered with a conductor layer, and a passage forming body is bonded on the opposite side surface to the substrate, allowing superconducting current to bypass through a stabilizing layer, reducing stress concentration and peeling stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multi-layer wire pieces are connected by soldering on the obverse (same side as superconducting layer), then connection resistance is reduced, but allowable stress in the tape longitudinal direction is reduced due to stress concentration
Solution Approach 1:
The patent inverts the conventional connection approach by bonding wire pieces at the reverse side (opposite to superconducting layer) instead of the obverse side. This inversion moves the bonding location away from the stress-critical superconducting layer region, reducing stress concentration while maintaining electrical connectivity through the stabilizing layer.
Solution Approach 2:
The patent transitions the connection location from the lateral dimension (obverse side) to the longitudinal dimension (reverse side), utilizing the stabilizing layer as a conductive path. This dimensional shift allows current to flow through the stabilizing layer to the bonding location, reducing impact on the superconducting layer's mechanical strength.
2Length of moving object
If wire length is extended to meet coil requirements, then coil functionality is improved, but stress concentration at connection ends increases and reduces allowable stress
Solution Approach 1:
The patent performs preliminary stress distribution design by positioning bonding locations at the reverse side before the wire is subjected to operational stresses. This preliminary configuration ensures that when the wire is extended and subjected to tension, the stress is distributed more evenly along the wire length rather than concentrating at the connection ends.
Solution Approach 2:
The stabilizing layer acts as an intermediary element that connects the superconducting layer to the bonding location at the reverse side. This intermediary structure allows mechanical strength to be maintained in the superconducting layer while providing a separate path for electrical connectivity and stress distribution.
3Reliability
If bonding is performed on the obverse side, then electrical connection is improved, but peeling stress destroys the laminated body including superconducting layer
Solution Approach 1:
The patent inverts the bonding location from the obverse side to the reverse side, placing the bonding operation away from the laminated body's critical superconducting layer. This inversion prevents peeling stress from acting on the laminated structure while maintaining electrical connectivity through the stabilizing layer's conductive path.
Solution Approach 2:
The patent extracts the bonding function from the obverse side location and relocates it to the reverse side. This extraction separates the electrical connection function from the mechanical integrity function, allowing each to be optimized independently - electrical connection through the stabilizing layer and mechanical integrity through the protected superconducting layer.
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 structure prevents the reduction of allowable stress in the tape longitudinal direction, maintains current density, and reduces the risk of thermal runaway by distributing stress effectively and maintaining superconductivity.
Implementation Method 1
a high-temperature superconducting layer formed on one surface of the substrate
Implementation Method 2
a passage forming body... which serves as a flowing path of a superconducting current generated in the high-temperature superconducting wire piece
Data Source
AI summary
A connection structure of a multi-layer wire includes at least a substrate, a high-temperature superconducting layer, a tape-type laminated body, a conductor layer, and a passage forming body. The high-temperature superconducting layer is formed on one surface of the substrate. The tape-type laminated body including at least the substrate and the high-temperature superconducting layer. The conductor layer covering an outer periphery of the tape-type laminated body. The passage forming body serving as a flowing path of a superconducting current generated in the high-temperature superconducting wire piece. The passage forming body is bonded by a bonding material is arranged on a side surface of the conductor layer, the side surface being located on an opposite side to the high-temperature superconducting layer with respect to the substrate.