FRP Truck Beam Web Structure for Short-Fill and Warpage Control
Solution Overview
Problem
Existing fiber-reinforced plastic materials face challenges in manufacturing structural components like beams due to issues such as short fill and warpage, leading to high scrap rates.
Innovation Solution
A structural part with a I-shaped cross-section beam made of fiber-reinforced plastic, featuring a web with varying thicknesses and a enlarged portion to act as a flow leader during molding, along with specific angles and orientations for mold opening, facilitating easier injection of molten plastic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If fiber-reinforced plastic material is used to manufacture structural beams, then vehicle weight is reduced, but manufacturing defects like short fill and warpage increase
Solution Approach 1:
The web thickness is varied locally along its length, with a first portion having a first thickness, a second portion having a second thickness greater than the first, and a third portion having a third thickness smaller than the second. This local variation in thickness creates regions of different stiffness and flow resistance, allowing the molten plastic to fill the mold cavity more uniformly and reducing warpage and short fill defects.
2Ease of manufacture
If constant web thickness is used in I-shaped beams, then manufacturing process is simpler, but molten plastic flow is difficult causing short fills
Solution Approach 1:
The web thickness parameter is changed along the length of the web, creating a non-uniform thickness profile. The second portion has a greater thickness than the first and third portions, which modifies the flow characteristics of the molten plastic during injection molding, enabling complete filling of the mold cavity without short fills.
3Manufacturing precision
If enlarged web portion is added to act as flow leader, then molten plastic injection is improved, but beam structural complexity increases
Solution Approach 1:
The enlarged second portion of the web serves multiple functions: it acts as a flow leader to guide molten plastic injection, provides additional structural reinforcement in a critical region, and creates a gradual thickness transition that reduces stress concentrations. This multi-functionality achieves manufacturing improvement without requiring separate flow leader components.
Data Source
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AI summary
The invention relates to a structural part (50) for a truck, comprising : a beam (10) made of fiber-reinforced plastic, the beam (10) having a I-shaped cross-section, the beam (10) comprising a web (3) extending from a first flange (1) to a second flange (2), in which a cross-section of the web (3) comprises : - a first portion (5) with a first thickness (T1), - a second portion (6) with a second thickness (T2), the second thickness (T2) being larger than the first thickness (T1), and - a third portion (7) with a third thickness (T3), the third thickness (T3) being smaller than the second thickness (T2), in which the second portion (6) is located between the first portion (5) and the third portion (7).