Variable Stiffness Hockey Stick Blade Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hockey stick manufacturing methods result in shafts with uniform cross-sectional geometries, which do not optimize bending stiffness and mass distribution, leading to suboptimal performance in terms of flexural rigidity and weight.
Innovation Solution
The method involves forming hockey stick shafts with variable cross-sectional geometries, such as pentagonal and heptagonal shapes, by wrapping fiber tape around a mandrel, inserting an inflatable bladder to apply pressure within a mold, and cooling to solidify the resin, resulting in a structure with increased second moment of inertia and reduced material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional uniform cross-sectional geometry is used, then manufacturing is simple, but bending stiffness is not optimized
Solution Approach 1:
The shaft is divided into multiple segments along its length, with each segment having a different cross-sectional geometry (e.g., pentagonal, heptagonal, rectangular). This segmentation allows optimization of bending stiffness in different regions while maintaining manufacturability through modular design
Solution Approach 2:
Different cross-sectional geometries are applied to different portions of the shaft based on local performance requirements. For example, the upper shaft may have a pentagonal cross-section for optimized bending stiffness in certain directions, while the lower shaft has a different geometry suited for its functional requirements
2Strength
If more material is used to increase bending stiffness, then flexural rigidity improves, but mass increases
Solution Approach 1:
The shaft is constructed using composite materials, specifically carbon fiber reinforced polymers, which provide high strength-to-weight ratio. The fiber orientation and layering are optimized to achieve maximum flexural rigidity with minimum mass
Solution Approach 2:
Instead of increasing material quantity, the design optimizes the distribution of material in different spatial dimensions through variable cross-sectional geometries. The non-uniform distribution of material across the cross-section and along the length achieves superior flexural rigidity without proportional mass increase
3Strength
If variable cross-sectional geometry is implemented, then bending stiffness is optimized, but manufacturing complexity increases
Solution Approach 1:
Traditional mechanical forming methods are replaced with automated fiber placement and resin infusion processes. These technologies enable complex variable cross-sectional geometries to be manufactured efficiently through digital modeling and automated control systems
Solution Approach 2:
The manufacturing process utilizes controllable parameters such as fiber orientation angles, layer thickness, and resin infusion pressure to achieve the desired variable cross-sectional geometries. By optimizing these parameters, complex shapes can be manufactured with standard equipment
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
This approach enhances bending stiffness while reducing the overall mass of the hockey stick, allowing for tailored flexural characteristics along the shaft length and improved energy transfer during puck or ball striking motions.
Implementation Method 1
the bladder may be expanded within the cavity to exert an internal pressure on the cavity to urge the fiber tape toward the walls of the mold
Implementation Method 2
the mold may be heated and the bladder may be expanded within the cavity
Implementation Method 3
The mold may be cooled and the bladder contracted and removed
Data Source
AI summary
A hockey stick apparatus may include a hollow shaft structure having a proximal end and a distal end, and a blade structure coupled to the proximal end of the hollow shaft structure. The blade structure may include a top edge spaced apart from a bottom edge by a blade height, a heel spaced apart from a toe by a blade length, a front face spaced apart from a back face by a blade thickness. The blade thickness may vary along the blade height, and the top portion of the blade may have a greater blade thickness than a blade thickness of the bottom portion, and a stiffened top portion of the blade may have a first stiffness and a flexible bottom portion of the blade may have having a second stiffness, and the second stiffness may be less than the first stiffness.