3D Printed Chassis With Self-Supporting Ribs
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Solution Overview
Problem
Conventional chassis structures, such as vehicle frames, require thick external walls to meet dynamic stiffness requirements, leading to increased mass and reduced fuel efficiency, and existing 3-D printing techniques still necessitate support structures that are difficult and costly to remove.
Innovation Solution
The use of self-supporting internal ribs in 3-D printed chassis structures, which serve as both stiffening and support elements, reducing the need for external support structures and allowing for thinner outer walls, thereby achieving dynamic stiffness while minimizing mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thick external walls are used in conventional chassis structures, then dynamic stiffness requirements are met, but mass increases and fuel economy decreases
Solution Approach 1:
The chassis structure is segmented into thin external walls and internal ribs as separate functional components. The thin walls (6-13 gauge steel) provide the outer shell while internal ribs (0.375-0.625 inches thick) provide structural support, allowing each component to be optimized independently for its specific function rather than requiring uniformly thick walls throughout.
Solution Approach 2:
The solution transitions from a two-dimensional approach (uniform wall thickness) to a three-dimensional approach by adding internal ribs that extend into the chassis cavity. This dimensional addition allows structural support to be distributed throughout the internal volume rather than concentrated in the external walls, reducing overall mass while maintaining stiffness.
2Ease of manufacture
If conventional 3-D printing support structures are used, then geometrically complex shapes can be produced, but post-processing removal is difficult and costly
Solution Approach 1:
The internal ribs serve a dual function: they provide structural support for the thin walls during service, and they act as self-supporting structures during the 3-D printing process. This eliminates the need for separate sacrificial support structures that would require post-processing removal, as the ribs are integral structural components from the start.
Solution Approach 2:
The internal ribs perform multiple functions simultaneously: they provide structural stiffening for the thin walls during vehicle operation, serve as support structures during the additive manufacturing process, and become permanent integral parts of the chassis. This multi-functionality eliminates the need for dedicated temporary support structures.
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 solution effectively meets high-frequency dynamic stiffness targets while reducing the overall mass of the chassis and eliminating the need for post-processing support structure removal, enhancing both performance and energy efficiency.
Implementation Method 1
The energy beam is applied to melt areas of the powder layer that coincide with the cross-section of the build piece in the layer. The melted powder cools and fuses to form a slice of the build piece.
Data Source
AI summary
Self-supporting 3-D printed chassis structures are disclosed. Self-supporting ribs are selectively printed to walls of the structure to meet desired dynamic stiffness targets while maintaining a reduced mass. The self-supporting ribs can be used as both support structures (e.g., for outer walls) during 3-D printing and as stiffening structures when the chassis structure is in operation. In an embodiment, the chassis structure is printed such that no support structures are needed. Topology optimization can enable remaining unneeded internal ribs or supports to be removed, and a high inner spatial volume between ribs can be maintained to make maximum use of the part. In various embodiments, wall thicknesses can be maintained at or below 1-2 millimeters, which further reduces mass.