Additive Manufacturing (3D Printing) and Optimization of Novel High-Energy Absorbing Composite Structures made from the Locally Produced Polypropylene

There are pressing needs to design new high-energy absorbing materials and structures to avoid catastrophic structural failures in automotive, aerospace, civil, and electronics applications. However, this is a challenging task since various mechanisms ? wave propagation, dynamic cracks, and delamination, thermal stresses, dislocation generation, growth, and motion ? are acting concurrently, at different material scales, and intertwined during impact. Heterogeneous and anisotropic materials have useful features for mitigating damage under impact because of various mechanisms for kinetic energy to be transformed. In this context, the main goal of this research project is to investigate, theoretically, computationally, and experimentally, new heterogeneous and anisotropic material systems in the micro and macro-scales. In particular, new manufacturing strategies will be developed to tailor composite structure of thermoplastics-elastomers, and thereby the materials? energy absorbing, deformation, and acoustic properties. Moreover, multiscale modeling and optimization tools will be established to help manufacturers streamlining the design validation phases of new products, and in turn significantly lower the related costs and shorten their product development cycle time. Rubber components are commonly used in many applications, in particular, latch bumper systems and door liners, which are used in various power and mechatronic systems in structural applications. These bumper systems provide deformation recovery, impact absorption and vibrational damping properties; however, they suffer from low stiffness and high stress relaxation. The proposed project aims at realization of new thermoplastic-based material systems, with high energy absorbing ability, superior mechanical damping property, acoustic properties, and tailored deformation recovery, to replace rubber. The realized material systems will represent a new class of material that offer combined elastomeric properties of crosslinked systems with the advantage of thermoplastic processability. Their improved processibility are strategically important to many applications traditionally relied on rubber-based materials. The materials? aging characteristics in simulated environmental conditions (e.g., temperature and humidity) will also be studied to elucidate the material properties after exposure to harsh environments anticipated during service, which will be a critical criterion for structural applications in order to fulfill safety regulations. Oman is a major producer of polymers like polypropylene and polyethylene which may be the seed of investing the locally produced raw polymers in high end polymeric products. In addition, this project will develop new multi-scaled models to elucidate the morphology-and-property relationships of hyperelastic material systems with different microscale phase morphologies. It will lead to a strategic tool to predict and optimize their deformation recovery, energy absorption, and mechanical damping behaviours. Together with finite element analysis in macroscale, shape and topology of elastomeric bumper components in automobiles? power and mechanical systems (e.g., latches of doors, sunroofs, trunk, and mechatronic systems), will be optimized to maximize their energy absorption, vibration damping, and deformation recovery abilities, as well as their durability. Successful completion of this project will represent a major contribution to research areas including ?Material Systems? as well as ?Process and Product Modeling? under the targeted area of ?Materials?. Developing novel heterogeneous and anisotropic high-energy absorbing material systems will lead to novel engineered structural material systems in conventional and emerging applications, including (i) automotive components with improved noise, vibration and harshness attributes; (ii) more resilient enclosures for portable-and-micro-electronics; and (iii) higher impact resistant outer layers for automotive and personal protective equipment applications. Furthermore, the proposed research will conduct theoretical and computational modeling of impact and energy absorbing behaviours of heterogeneous material systems with tailored micro and macro-scale architectures. Experimental characterization and constitutive modeling of strain rate-dependent polymer matrix material systems, and their implementation in micromechanics models and nonlinear finite element code for impact and failure analysis will be investigated. The resulting models that describe the structure-property relationships of high-energy absorbing material systems will accelerate and optimize the development of products or materials.