Adhesive-Bonded Wood Element Joints for End-to-End Load Transfer
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Solution Overview
Problem
Existing methods for connecting wooden elements, particularly for end-to-end applications, are limited by size constraints, require expensive and visually intrusive metal fasteners, and do not effectively transfer tensile and compressive forces, while on-site connections are hindered by adhesive bonding limitations and transport restrictions.
Innovation Solution
A method of bonding wooden elements end-to-end by aligning their principal fiber directions and using an adhesive layer to transfer forces between the fibers, allowing for simple, cost-effective, and durable connections that can be made on-site without damaging the wood or increasing component size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal fasteners are used to connect wooden elements, then the connection can withstand high compressive and tensile forces, but the cost increases, the visual appearance is disturbed, and the wood structure is weakened by insertion points
Solution Approach 1:
The patent replaces the mechanical connection system (metal fasteners, screws, nails) with a chemical bonding system (adhesive). The adhesive forms a bonding layer between the first and second wooden elements, transferring forces through adhesion and cohesion rather than mechanical interlocking. This substitution eliminates the need for fastener insertion, thereby preventing damage to the wood structure while maintaining connection strength.
2Length of moving object
If wooden elements are cut to larger sizes to overcome transportation limitations, then the component size increases, but the elements become more difficult to handle and transport
Solution Approach 1:
The patent divides a large wooden component into multiple smaller wooden elements that can be easily handled and transported separately. These segmented elements are then connected through adhesive bonding to form the complete large-scale structure. This segmentation allows the component to exceed the length limitations of individual tree trunks while maintaining ease of handling during transport and assembly.
Solution Approach 2:
The wooden elements are prepared and adhesive-bonded together in a controlled environment (such as a factory) before final assembly. This preliminary bonding creates pre-assembled units that are optimized for transport, and the final on-site assembly requires minimal handling, thus resolving the contradiction between large component size and ease of operation.
3Ease of manufacture
If adhesive bonding is used to connect wooden elements end-to-end, then the connection can be made on site without metal fasteners, but the adhesive must withstand high tensile and compressive forces
Solution Approach 1:
The patent optimizes the adhesive connection by controlling the thickness of the bonding layer and the surface area of contact between wooden elements. By adjusting these parameters, the adhesive can distribute and withstand high tensile and compressive forces effectively. The bonding layer thickness is controlled to ensure sufficient adhesive material while maintaining structural integrity, enabling on-site assembly without metal fasteners.
Solution Approach 2:
The patent creates a composite structure consisting of wood and adhesive working together. The adhesive bonding layer, with its specific mechanical properties, complements the wooden elements to form a unified load-bearing structure. This composite approach allows the adhesive connection to withstand high forces while maintaining ease of on-site assembly.
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
Enables the production of wooden components of any size that can withstand high tensile and compressive forces, eliminating the need for metal fasteners and allowing for on-site construction, while maintaining the integrity and appearance of the wood.
Implementation Method 1
The forces from the fibers of the first wooden element are transferred to the fibers of the second wooden element through adhesive bonding of the first wooden element with the second wooden element
Implementation Method 2
The adhesive layer now transfers the introduced force to the neighboring wooden element
Data Source
Figure 1~2
Figure 3~4
Figure 5~5A
AI summary
The component (100) according to the invention has a first wood element (110) with at least a first main grain direction (114) and a second wood element (120) with at least a second main grain direction (124). At the end, and spaced apart, the first wood element (110) is adhesively bonded, on a first side cutting through the first main grain direction (114), to a first side (121) of the second wood element (120) cutting through the second main grain direction (124).