Shear Wall Fastener Shank Geometry for Better Retention
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Solution Overview
Problem
Existing fastener designs, particularly those with diamond points, often create enlarged holes in fastening materials, leading to reduced retention and increased slip in shear wall systems, compromising the structural integrity and energy efficiency of the connection.
Innovation Solution
The fastener design incorporates a shank with a diamond point and an enlarged cylindrical region under the head, featuring grooves or ridges to enhance pullout resistance and minimize slip, ensuring a tighter fit with the fastening material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a diamond point is formed on the fastener, then the fastener can penetrate the fastening material more effectively, but an enlarged area at the intersection of the shank and point is created which adversely affects retention
Solution Approach 1:
The fastener shank is designed with varying diameters at different locations: a first diameter in the first region, a second diameter in the second region, and a third diameter in the third region. This local variation in geometry allows the fastener to have optimal penetration characteristics at the point while maintaining optimal retention characteristics in the embedded regions, resolving the contradiction between penetration effectiveness and retention.
2Reliability
If the shank diameter is increased to improve retention, then the tightness of fit improves, but the fastener complexity increases
Solution Approach 1:
The shank is divided into three distinct regions along its length, each with a specific diameter optimized for its function. The first region has a first diameter, the second region has a second diameter, and the third region has a third diameter. This segmentation allows each region to be optimized independently for its specific role while maintaining overall structural integrity.
Solution Approach 2:
The fastener employs controlled variations in the shank diameter parameter along its length. By changing the diameter parameter from the first diameter to the second diameter to the third diameter at different locations, the fastener achieves optimal performance for both penetration and retention without requiring complex additional features.
Data Source
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AI summary
A fastener (10) comprises a shank (100) having a first end having a point (102) and a second end having a head (104). The shank (100) includes a first region (110) beginning at the first end and having a cylindrical cross-section with a first diameter (D1) along at least a portion of the first region (110); and a second region (112) extending from the first region (110) to the head (104) and having a cross section with a second diameter (D2) greater than the first diameter (D1). The first region (110) may include a distortion adjacent the tip encompassing at least a portion of a surface of the first region (110), the distortion having a third diameter greater than the first diameter (D1) and less than or equal to the second diameter (D2).