Direction-Adjustable Bolted Spherical Joint for Collapse Resistance
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Solution Overview
Problem
Existing bolted spherical joints in spatial grid structures are prone to failure due to low-cycle fatigue, leading to structural collapse during earthquakes, and suffer from installation difficulties caused by machining inaccuracies.
Innovation Solution
A direction-adjustable bolted spherical joint is designed, featuring a connecting component with a threaded barrel, connecting rod, and threaded cap, which provides tensile capacity, compression resistance, and adjustable locking strength to enhance collapse resistance and earthquake resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional bolted spherical joint is used for fast installation, then installation efficiency is improved, but the joint is prone to failure due to low-cycle fatigue cumulative damage during earthquakes
Solution Approach 1:
The connecting component is divided into multiple functional parts: a threaded barrel for tensile connection, a threaded cap for compression resistance, and a ball head for positioning. This segmentation allows each part to specialize in resisting specific types of loads, improving overall reliability while maintaining fast installation capabilities.
Solution Approach 2:
The joint employs composite structural design combining different material properties in the connecting component - the threaded barrel provides tensile strength, the threaded cap provides compression resistance, and the ball head provides positioning accuracy. This composite approach enhances earthquake resistance while preserving installation efficiency.
2Ease of manufacture
If machining accuracy is not controlled, then manufacturing cost is reduced, but installation becomes difficult due to non-coaxial alignment between bolt ball and member
Solution Approach 1:
The ball head is designed with a spherical shape that can rotate and adjust its orientation during installation. This dynamic characteristic allows the connecting rod to self-align with the bolt ball even when machining accuracy varies, eliminating installation difficulties while maintaining cost-effective manufacturing.
Solution Approach 2:
The spherical geometry of the ball head changes the alignment parameter from rigid coaxial requirement to angular flexibility. This parameter change allows the joint to accommodate machining variations and achieve proper alignment during on-site installation without increasing manufacturing complexity.
3Manufacturing precision
If forced installation is performed to achieve alignment, then installation accuracy is improved, but internal stress is introduced into the structure
Solution Approach 1:
The spherical ball head can rotate freely during installation to achieve alignment, eliminating the need for forced installation. This dynamic adjustment capability achieves accurate alignment without introducing internal stress into the structure, as the joint adapts naturally to the installation geometry.
Solution Approach 2:
The spherical shape of the ball head converts the potential harm of alignment difficulty into a benefit by enabling self-alignment. Instead of requiring forced installation to achieve precision, the spherical geometry allows the joint to naturally find its correct orientation, eliminating internal stress while maintaining accuracy.
4Quantity of substance
If the spatial grid structure has low redundancy, then material usage is optimized, but joint failure leads to continuous collapse of the whole structure
Solution Approach 1:
The connecting component is segmented into multiple load-bearing elements (threaded barrel, threaded cap, ball head) that work together to distribute stresses. This segmentation provides local redundancy within the joint, preventing total structural collapse even when the overall spatial grid structure has low material redundancy.
Solution Approach 2:
The threaded cap is designed to provide compression resistance before tensile failures occur during earthquake loading. This beforehand cushioning in the compression direction prevents catastrophic joint failure, thereby protecting the overall structure from collapse even with optimized material usage.
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 direction-adjustable bolted spherical joint effectively increases the locking strength and resistance to collapse and earthquakes, while simplifying installation and ensuring stress balance, thus improving the structural integrity of spatial grid structures.
Implementation Method 1
a connecting rod (2) penetrates into the threaded barrel (3) and is clamped into the threaded barrel (3)
Implementation Method 2
A spatial grid structure has become a promising spatial structure owing to its reasonable stress
Data Source
AI summary
Provided is a direction-adjustable bolted spherical joint for collapse resistance and earthquake resistance. The joint includes a connecting component, disposed between a bolt ball and a member. The connecting component includes a threaded barrel, the threaded barrel is screwed into a connecting hole on the bolt ball, a connecting rod is clamped into the threaded barrel, a threaded cap is screwed onto the connecting rod, and an end of the threaded cap facing towards the threaded barrel is embedded into the threaded barrel. The connecting rod includes a ball head, the ball head is abutted against an end of the threaded barrel disposed in the bolt ball, the ball head is fixedly connected to a rod body, the rod body is disposed to pass through the threaded barrel and extend out of the bolt ball, and the threaded cap is screwed onto the rod body.