Timber Connection Assembly Using Friction-Grip Bolts for Moment Resistance
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Solution Overview
Problem
Existing timber connections for large buildings suffer from low moment-resisting properties, stiffness, energy dissipation, and assembly complexity, leading to potential failure under high cyclical loads and limited modularity, which hinders the use of timber in large-scale construction.
Innovation Solution
A connection system using oversized holes and friction grip bolts, allowing for easy assembly and disassembly, enhanced mechanical performance, and improved energy dissipation, featuring elongated anchor members fixed to timber members to resist moments and withstand temperature and moisture fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional timber connections use tight-fitting holes with bolts passing through the entire thickness, then moment-resisting properties are improved, but the connection becomes sensitive to temperature and moisture fluctuations causing over-tightening or loosening
Solution Approach 1:
The patent changes the hole dimension parameter from tight-fitting to oversized (e.g., 6mm oversized), fundamentally altering how the connection handles dimensional changes. This parameter change allows the connection to accommodate temperature and moisture-induced movements without compromising moment-resisting capacity or reliability
Solution Approach 2:
The oversized hole acts as a pre-designed cushion or buffer that anticipates and absorbs the effects of thermal expansion and moisture-induced dimensional changes. This beforehand cushioning prevents the bolt from becoming over-tight or loose, maintaining connection reliability under environmental fluctuations
2Stability of the object's composition
If known timber connections are designed to resist moments, then connection stability is improved, but stiffness remains low and energy dissipation capability is insufficient
Solution Approach 1:
The patent employs a composite connection system combining steel bolts with timber members, where the steel components provide high stiffness and strength while the timber provides ductility and energy absorption. This composite approach achieves both stability and enhanced strength characteristics
Solution Approach 2:
The patent utilizes curved or angled grain direction arrangements in the timber members around the bolt holes, optimizing the natural fiber curvature to enhance both stiffness and energy dissipation capabilities while maintaining connection stability
3Adaptability or versatility
If traditional timber connections are assembled on site with extensive drilling and adhesive application, then connection customization is possible, but assembly time and labor cost increase significantly
Solution Approach 1:
The patent applies adhesive in advance during factory fabrication rather than on-site assembly. The timber members are pre-assembled and bonded in controlled factory conditions, then transported as complete units. This preliminary action eliminates time-consuming on-site adhesive application and drilling operations
Solution Approach 2:
The patent divides the building into modular segments that can be pre-assembled with connections in a factory setting. These standardized modules maintain adaptability through design flexibility while dramatically reducing on-site assembly time through simple connection operations
4Ease of manufacture
If known timber connections are used in buildings, then initial construction is possible, but the building cannot be easily disassembled or reconfigured for future modifications
Solution Approach 1:
The patent creates a dynamic connection system using oversized holes that allow for both rigid initial assembly and flexible future disassembly. The same connection detail that provides stability during construction also enables easy modification later, as bolts can be removed and repositioned without damaging structural components
Solution Approach 2:
The oversized hole design allows connectors and timber members to be recovered intact after disassembly. Components can be removed, inspected, and reused in reconfigured building layouts, extending the building's useful life and enabling adaptive reuse without material waste
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 connection system supports greater spans and rigidity, reduces assembly time and cost, and enables modular building configurations, making timber a viable alternative to steel and concrete in large-scale construction.
Implementation Method 1
The or each bolt may be configured to clamp the plate and anchor member such that relative movement of the plate and first connector assembly is resisted, for example by friction caused by the clamping force provided by the plurality of bolts.
Data Source
AI summary
A connection, a kit of parts, a modular building and associated methods. The connection comprising: a first timber member; a first connector assembly associated with the first timber member, the first connector assembly comprising: a plurality of elongate anchor members, each anchor member comprising a first end extending into and fixed with respect to the first timber member; and a second end protruding from the first timber member, wherein each of the anchor members defines a hole perpendicular to a longitudinal axis of the anchor member for receiving a bolt; the connection further comprising: a plate connected or connectable to a second member, the plate defining at least one hole for receiving a bolt; at least one plurality of bolts, the or each bolt configured to extend through at least one of the anchor members and plate; wherein for the or each bolt, at least one of the corresponding anchor member hole or plate hole is oversized so as to receive the corresponding bolt with a clearance fit; and the or each bolt is configured to clamp the plate and anchor member such that relative movement of the plate and first connector assembly is resisted by friction caused by the clamping force provided by the plurality of bolts.