# Process modeling of liquid composite molding processes

Da W​u, Doctoral Student at Material and Computational Mechanics​ IMS, defends his doctoral thesis.

Whenever you decide to buy a new pair of skis,  have you asked why they are so expensive? When you ride your fantastic carbon road bike, are you curious to know how the bike is made? To answer these questions, we need to explore the topic of the manufacturing of polymer composite materials.

Da Wu will defend the thesis (online) on May 12. A popular science summary is given below. For more information, see the links at the bottom of the page.​

Process modeling of liquid composite molding processes
Composite materials are the most advanced and adaptable engineering materials known to man. They are only a few decades old, but the evolution of composites and manufacturing process is rapid. All manufacturing techniques aim to bind fiber reinforcements together with polymer matrices. The matrix gives the composite shape, appearance, and durability. At the same time, the fiber reinforcement carries the structural loads to provide stiffness and strength.  Any successful composite manufacturing process boils down to how to control temperatures and pressures throughout the process. Sufficient pressure can force the matrix to fill out the entire fiber bed, and the right temperature held for a suitable period will stabilize the dimensions of composites. Due to the flexible combinations of pressures and temperatures, it is very difficult to tell if one process is good. The balance between high properties and low costs challenges all manufacturers. The trial-and-error approach is avoided, but the virtual numerical experiment is emerging. To develop a good numerical solution, we need to understand the physical mechanism and build mathematical models for the selected process.

In this thesis, we define the problem of the liquid composite molding process and formulate the problem as mathematical equations through fundamental continuum mechanics. We also made assumptions to simplify the problem. Once the model is developed,  we verify and validate the model. By using the proposed model, we can run simulations on computers to mimic the real manufacturing process of polymer composites. Now, you may answer the questions asked at the beginning by yourself, if you run our model with some settings and clicks.

Published: Wed 06 May 2020.