Concave-convex Sheet Material Stiffness Weight Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sheet materials with concave-convex shapes for weight reduction and stiffness enhancement in vehicles face limitations in achieving optimal stiffness and weight reduction effects, with existing solutions providing only a two-fold stiffness increase and 20% weight reduction, and often exhibiting stiffness anisotropy and material cost issues.
Innovation Solution
A sheet material design featuring a concave-convex pattern with specific virtual plane references, unit areas, and lattice partitioning, where first and second areas protrude from intermediate reference planes to form icosagonal areas, enhancing material distribution and second moment of area, thereby improving bending stiffness and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional embossed concave-convex parts are formed in sheet material, then stiffness is increased, but the stiffness increase effect is limited to approximately two times and weight reduction effect is limited to approximately 20%
Solution Approach 1:
The invention applies curvature by forming concave-convex parts with specific radii of curvature (R1, R2, R3) in the sheet material. The convex parts have a radius of curvature R1, and the concave parts have radii R2 and R3, creating a three-dimensional curved surface structure that significantly enhances stiffness through geometric reinforcement rather than simply adding material thickness.
Solution Approach 2:
The invention transitions from a two-dimensional flat sheet to a three-dimensional structured surface by forming protruding convex parts and recessed concave parts. This dimensional transformation creates a complex topography that increases the second moment of area and provides superior stiffness enhancement compared to conventional planar embossed patterns.
2Strength
If sheet thickness is increased to ensure required stiffness, then stiffness is improved, but weight reduction goals are compromised
Solution Approach 1:
The invention uses curvature to achieve stiffness enhancement without increasing thickness. By forming convex parts with radius R1 and concave parts with radii R2 and R3, the sheet material gains structural rigidity through geometric form rather than material quantity, maintaining lightweight characteristics while meeting stiffness requirements.
Solution Approach 2:
The invention resolves the thickness-stiffness tradeoff by moving from a two-dimensional thickness increase strategy to a three-dimensional surface structuring approach. The concave-convex pattern creates vertical dimensionality through protrusions and recesses, providing stiffness enhancement that does not require increasing the base sheet thickness.
Data Source
AI summary
A sheet material (1) includes a stiffness-increasing concave-convex part (20). A first reference plane (K1), an intermediate reference plane (K3), and a second reference plane (K2) serve as a reference system. First unit areas (241) and second unit areas (242) are defined in the intermediate reference plane (K3). Each of the first unit areas (241) and the second unit areas (242) contains first virtual squares (243) and second virtual squares (244). Icosagonal areas that contain only adjacent first virtual squares (243) are designated as first reference areas (213), and icosagonal areas that contain only adjacent second virtual squares (244) are designated as second reference areas (223). The concave-convex part (20) contains first areas (21), which are formed based on the first reference areas (213), as well as second areas (22) and/or plane areas (23), which are formed based on the second reference areas (223).