Analysis of PDCPD Material Application for Heavy-Duty Truck Lightweighting

1 Lightweighting Technology

1.1 Overview of Lightweighting

Automotive lightweighting technology involves the use of new design methods, manufacturing techniques, and materials to redesign and manufacture components. This is done on the basis of ensuring the functional and aesthetic performance requirements of the parts, with the aim of minimizing the product's own weight to achieve performance indicators such as weight reduction, lower energy consumption, safety, and environmental protection.
With the continuous advancement of new material technologies and design/manufacturing techniques, the application of automotive lightweighting is increasing. The application of PDCPD reduces product weight by 30%-50% while maintaining the comprehensive performance of automotive exterior parts. This provides potential for development in reducing the overall vehicle weight, lowering energy consumption, and enhancing environmental protection and safety.

1.2 Introduction to New Lightweighting Materials

Polydicyclopentadiene (abbreviated as PDCPD) is a thermosetting resin, also known as "plastic steel," and is a new type of engineering plastic.
PDCPD is a polymer produced from the monomer dicyclopentadiene (DCPD), which is derived from the C5 fraction of ethylene cracking. The purity is refined to 99.8%, and then, under the action of a catalyst, it undergoes ring-opening metathesis polymerization.
PDCPD material weighs about 60% of SMC material; it has good coating performance and is compatible with various paints and coatings. The conventional mechanical properties and reliability of PDCPD are similar to those of SMC, and it has good impact resistance, making it suitable for application in automotive components to achieve lightweighting goals. During the part molding process, the material's properties can be further enhanced by adding various additives (such as flame retardants, reinforcing agents, etc.).

2 Application of PDCPD Material

2.1 Product Structural Design Characteristics with the New Material

Compared to traditional injection molding or hot press molding products, PDCPD products offer advantages such as good raw material flowability, resulting in parts with high design freedom, excellent impact resistance, low coefficient of expansion, and good resistance to high and low temperatures. They can be used in extremely cold regions without becoming brittle or cracking. During product design, the inherent characteristics of the material should be fully considered. Without changing the appearance requirements of the part, the internal structure should be designed in a mesh-like or skeleton-like (ribbed) form as much as possible, leveraging the material's properties to reduce product weight while ensuring strength.

2.2 Molding Process Characteristics of the New Material

This material is formed using Reaction Injection Molding (RIM). This process involves the high-velocity impingement mixing of two highly chemically active, low relative molecular weight component materials, which are then injected into a sealed mold at room temperature and low pressure. Inside the mold, chemical reactions such as polymerization, cross-linking, and curing are completed to form the product . This new process, which combines polymerization reaction with injection molding, features high mixing efficiency, good flowability, flexible formulation of raw materials, short production cycles, and low cost. It is suitable for producing large, complex parts with non-uniform wall thicknesses.

3 Application of Lightweight Automotive Exterior Parts Based on Design

Lightweight structural design analysis is conducted through improved component design, initial structural design, product manufacturing, and prototype evaluation. Under the premise of meeting performance requirements, optimized design is used to eliminate redundant sections of parts, reduce part overlaps or mounting structures, and design structures in a mesh or skeleton-like manner based on ensuring strength, thereby achieving lightweighting.

3.1 Optimized Design

Optimized design mainly involves two aspects: firstly, developing new design methods based on material characteristics to optimize the part's shape design [3]; secondly, designing new structural shapes to optimize the part's form according to actual working conditions.

3.2 Case Study of Exterior Part Optimized Design

Overall, PDCPD material performance is superior to SMC in all aspects except static strength, making it suitable for general appearance parts. It is particularly advantageous for components requiring high toughness, impact resistance, aging resistance, exterior coating performance, and environmental protection, where PDCPD offers better comprehensive performance. CAE Analysis: HyperMesh was used for pre-processing; OptiStruct was used for solving; HyperView was used for post-processing. Analysis was conducted under three working conditions: vertical loading, steering, and braking. The CAE analysis confirmed that the product structure meets the performance requirements.

4 Conclusion

Comprehensive analysis leads to the following conclusions: PDCPD, as a new plastic material, offers advantages in lightweighting, environmental protection, low-temperature resistance, and aging resistance. Especially its good toughness in low-temperature environments makes it suitable for replacing traditional products in automotive interior and exterior applications. Due to its inherent characteristics, it is well-suited for manufacturing automotive exterior cover parts and interior trim components. This study verifies the feasibility of applying PDCPD new material in certain exterior parts.