Announcements

Mr. Saeed Behseresht is a PhD candidate in mechanical engineering at New Mexico State University, United States. He began his research in additive manufacturing in 2022, focusing on process optimization and finite element analysis (FEA) modeling of polymers. His current work extends to metal additive manufacturing, with an emphasis on melt pool characterization in Wire Arc Additive Manufacturing (WAAM) and Laser Powder Bed Fusion (LPBF). He develops advanced simulation tools, including custom Abaqus subroutines, to predict residual stress, warpage, and microstructural evolution, supporting the production of defect-free components. Additionally, he integrates machine learning, reinforcement learning, and AI-based process monitoring to ensure part quality and process safety in metal AM. In addition to his research, he has experience teaching courses in engineering analysis and mechanical testing, and supervising student projects related to modeling, process optimization, and additive manufacturing. His work aims to bridge fundamental research and practical applications, advancing additive manufacturing technologies for industrial use.

Dr. Young Ho Park is a Professor in the Department of Mechanical and Aerospace Engineering at New Mexico State University (NMSU), United States. He earned his PhD in Mechanical Engineering from the University of Iowa in 1994. Dr. Park’s research and professional interests span a broad range of topics, including metal additive manufacturing (WAAM), polymer additive manufacturing (FDM), computational mechanics, engineering design and optimization, fiber-reinforced composite materials, structural damage diagnosis and prognosis, fatigue life prediction and reliability analysis, and atomistic and multiscale modeling of nanosystems. He has successfully secured research grants from government agencies and industry partners, including the USDoD, USDA, USBR, NASA, Los Alamos National Laboratory, and Sandia National Laboratories. Dr. Park is an active member of the American Society of Mechanical Engineers (ASME) and serves on the editorial board of Multiscale and Multidisciplinary Modeling, Experiments and Design (Springer). At NMSU, he teaches courses in solid mechanics.

Based on the positive evaluations by the reviewers and academic editors for Mr. Saeed Behseresht’s group article, we have selected their article as the newsletter article for further promotion.

“Additive Manufacturing of Composite Polymers: Thermomechanical FEA and Experimental Study”
by Saeed Behseresht and Young Ho Park
Materials 2024, 17(8), 1912; https://doi.org/10.3390/ma17081912

The following is an interview with Mr. Saeed Behseresht:

1. Congratulations on your published paper. Could you please briefly introduce the main research content of the published paper?

Thank you very much for your interest in our research and for inviting us to this interview for your journal. I would also like to thank my PhD advisor, Dr. Young Ho Park, for his professional and fruitful cooperation and mentorship.

In this work, we developed a thermomechanical finite element framework to simulate the additive manufacturing process of semi-crystalline carbon fiber-reinforced polymers produced via Fused Filament Fabrication (FFF). Specifically, we focused on 50 wt.% carbon fiber-reinforced polyphenylene sulfide (CF-PPS), a high-performance composite polymer widely used in heavy-duty sectors like aerospace. Our model accounts for heat transfer, crystallization, viscoelastic behavior, shrinkage, and anisotropy to predict residual stresses and warpage. We implemented several Abaqus user subroutines, including UMAT, UMATHT, ORIENT, and UEPACTIVATIONVOL, to capture complex material responses. The simulations were validated against experimental measurements and showed strong agreement, underscoring the reliability of our approach.

2. What are the key takeaways you hope readers will gain from your paper?

There are several key takeaways that authors may benefit from. First is an accurate simulation of residual stresses and distortions in fiber-reinforced composite polymers that requires integrating thermal, mechanical, and crystallization effects into a unified framework. Next are user-defined subroutines that allow researchers to go beyond built-in AM modeling capabilities, enabling more realistic representations of anisotropic composites. Furthermore, validated models can be powerful predictive tools to optimize print parameters and reduce costly trial-and-error experimentation in industrial-scale additive manufacturing.

3. Was there a specific experience or event in your research career that led you to focus on your current field of research?

Yes. My background in finite element modeling and mechanics of materials naturally aligns with challenges in additive manufacturing, particularly in understanding defects such as warpage and residual stresses. Early in my doctoral work, I observed the gap between experimental observations of distortions in printed composites and the limited predictive capability of existing models. This gap motivated me to develop more comprehensive simulation tools that couple thermal, crystallization, and mechanical phenomena.

4. Could you describe the difficulties and breakthrough innovations encountered in your current research?

One of the main difficulties was accurately modeling the complex interplay between thermal history, crystallization kinetics, and the anisotropic viscoelastic response of the polymer matrix. Conventional finite element solvers are not equipped to handle all of these interactions simultaneously. The breakthrough came from developing customized subroutines that integrate non-isothermal crystallization kinetics with mechanical constitutive modeling, enabling us to realistically capture shrinkage and stress evolution. Another innovation was validating our approach through both Abaqus AM Modeler comparisons and physical experiments, which increased the robustness of the findings.

5. Does technological progress provide new opportunities for the topic you are researching? Does it bring any potential risks? How do you think these factors will affect future research trends on this topic?

Technological progress in both hardware (e.g., advanced printers, in situ monitoring, sensors, etc.) and software (e.g., Multiphysics solvers, machine learning integration) provides tremendous opportunities to refine predictive models and enable real-time control of the printing process. The risks lie in reliance merely on black-box models without sufficient physical grounding, which may lead to inaccurate predictions in safety-critical applications like aerospace or medical. Looking ahead, I expect research trends to emphasize hybrid approaches that combine physics-based simulations with data-driven techniques, ensuring both accuracy and efficiency.

6. How do you evaluate research trends in this field, and what advice would you give to other young researchers?

Research in additive manufacturing of composites is moving rapidly toward multi-scale and Multiphysics approaches, bridging process modeling with microstructural and performance predictions. My advice to young researchers is to develop both strong fundamentals in mechanics and numerical methods, and an openness to interdisciplinary collaboration, whether in materials science, process control, or computational methods. Striking this balance allows one to make meaningful contributions to both theoretical advances and practical industrial needs.

7. What appealed to you about the Materials journal that made you want to submit your paper? In your opinion, what can authors expect when they submit to Materials?

Materials is a well-recognized open access journal with a broad readership across disciplines, which makes it an excellent venue for research that sits at the intersection of materials science, mechanics, and manufacturing. The journal’s emphasis on both fundamental and applied studies appealed to us, since our work is both methodological and industrially relevant. Authors can expect a rigorous but constructive peer-review process, a timely publication cycle, and wide dissemination of their work.

8. What is your experience publishing with Materials?

Our experience has been very positive. The submission and review process was straightforward, the reviewers provided constructive feedback that helped strengthen the manuscript, and the editorial office was efficient in handling communications. The open access format also ensured immediate visibility of the work to a global audience.

9. How do you think the open access way of publishing impacts authors?

Open access publishing greatly enhances the visibility and accessibility of research, particularly in fields like additive manufacturing, where collaboration between academia and industry is essential. Authors benefit from higher citation potential and broader readership, including engineers and practitioners who may not have institutional access to subscription journals. Another positive aspect for me is that the open access format, particularly when it comes with publication support such as the full discount we received, makes research more accessible and helps decentralize knowledge, ensuring that scholarly work can reach a wider audience without financial barriers.