Gert Haunch Moment Frame Connection for Seismic Resilience
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Solution Overview
Problem
Existing structural systems are prone to catastrophic collapse during seismic and wind events due to increased stiffness from thicker structural members, which limits their ability to flex and absorb forces, leading to near-complete structural failure and unrepairable damage.
Innovation Solution
The Gert Haunch connection system, featuring a bend plate that acts as a ductile fuse, allows for energy dissipation and maintains the structure's elasticity, with a replaceable haunch and top plate design that accommodates various column sizes and materials, providing additional strength and stiffness while allowing for flexible deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thicker structural members are used to increase overall strength, then strength is improved, but flexibility deteriorates
Solution Approach 1:
The connection system is divided into separate functional components: a haunch for strength, a bend plate for flexibility and energy dissipation, and a retainer plate for securing. This segmentation allows each component to optimize its specific function without compromising the other, resolving the contradiction between strength and flexibility.
Solution Approach 2:
Different regions of the connection system have different properties: the haunch provides local strength where needed, while the bend plate provides local flexibility and ductility. This local differentiation allows the overall system to simultaneously achieve both strength and flexibility by having each region perform its optimized function.
2Strength
If thicker structural members are used to increase overall strength, then strength is improved, but ductility deteriorates
Solution Approach 1:
The connection is segmented into a haunch (for strength) and a bend plate (for ductility). The bend plate acts as a dedicated ductile element that can deform plastically to dissipate energy during seismic events, while the haunch maintains the overall strength. This segmentation preserves ductility despite using thicker members.
Solution Approach 2:
The bend plate serves as an intermediary element between the haunch and the column. It mediates the force transmission by providing a ductile deformation mechanism that protects the more rigid haunch and column from catastrophic failure, thus maintaining system reliability during lateral force events.
3Strength
If the structure is made stiffer to resist failure, then strength is improved, but repairability deteriorates
Solution Approach 1:
The connection system is segmented into replaceable components, particularly the bend plate and retainer plate. If damage occurs during an earthquake, these modular components can be independently removed and replaced without affecting the entire structure, significantly improving repairability while maintaining the overall strength provided by the haunch.
4Strength
If larger structural members are used to increase strength, then strength is improved, but device complexity increases
Solution Approach 1:
The connection is segmented into standardized components (haunch, bend plate, retainer plate) that can be manufactured separately and assembled together. This modular approach reduces overall complexity by allowing each component to be optimized independently and facilitates easier fabrication, shipping, and installation compared to a monolithic design.
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 Gert Haunch connection enhances the structural system's ductility and flexibility, enabling it to absorb lateral forces effectively, reducing the risk of collapse and allowing for easier replacement of damaged components post-event, thus improving resilience and reducing material costs.
Implementation Method 1
The bend plate acts as a ductile fuse, allowing for energy dissipation and maintains the structure's elasticity
Implementation Method 2
The bend plate acts as a ductile fuse, allowing for energy dissipation and maintains the structure's elasticity
Implementation Method 3
allowing for flexible deformation
Implementation Method 4
A first edge of the retainer plate is separated from a second haunch side by a yielding region
Data Source
AI summary
A system, method and apparatus of connecting a beam to a column includes a haunch including a first haunch side coupled to a first side of the beam and a bend plate secured to a first end of the haunch. The haunch is coupled to the column by the bend plate separated from the column by a spacer plate. A top plate extends a first distance along a top surface of the beam and the top plate includes a column opening encompassing the column, the top plate is secured to the top surface of the beam. A first edge of the spacer plate can be separated from a second haunch side by a yielding region, wherein the second haunch side is opposite from the first haunch side. The bend plate can be welded to the first end of the haunch.