Mechanical properties of 3D printed macroscopic models of schwarzites

Rheological Analysis of 3D Printed Elements of Acrylonitrile Butadiene and Styrene Material Using Multiparameter Ideal Body Models

The growing application of additive technologies in various industrial fields determines the undertaking of research in this direction. The need to study mechanical properties, including rheological properties, is necessitated by the use of additively manufactured models as utility models. Furthermore, the values of mechanical properties are affected by the technological parameters of 3D printing. One of the popular engineering materials used in 3D printing is acrylonitrile butadiene and styrene, commonly known by the abbreviated name ABS, which is quite hard and resistant to high temperatures. This article presents a study of the rheological properties of ABS material using multiparameter ideal body models. Two rheological phenomena of stress relaxation and creep were evaluated. The effects of two technological parameters, layer height and printing direction, on the resulting values of elastic moduli and dynamic viscosity coefficients were also evaluated. The elastic moduli and dynamic viscosity coefficients were calculated using the Maxwell-Wiechert and Kelvin-Voight models. The study showed the effect of layer height on rheological properties. Moreover, very good fit was obtained between the multiparameter rheological models and the experimental curves, which are shown by the average value of χ 2 ¯ = 0 . 001 and R 2 ¯ = 0 . 9991 . The presented research can be used by designers to design machine parts or car or aircraft components. Moreover, research expands knowledge of the mechanical properties of additively manufactured parts.

High-Throughput Screening of 3D-Printed Architected Materials Inspired by Crystal Lattices: Procedure, Challenges, and Mechanical Properties

The search for load-bearing, impact-resistant, and energy-absorbing cellular materials is of central interest in many fields including aerospace, automotive, civil, sports, packaging, and biomedical. In order to achieve the desired characteristic geometry and/or topology, a perspective approach may be used, such as utilization of atomic models as input data for 3D printing of macroscopic objects. In this paper, we suggest a new approach for the development of advanced cellular materials-crystallomorphic design based on selection of perspective crystal structures and modeling of their electron density distribution and utilization of isoelectronic surfaces as a generatrix for 3D-printed cellular materials. The ATLAS database, containing more than 10 million existing and predicted zeolites, was used as a source of data. Herein, we introduced a high-throughput screening of a data array of crystalline compounds. Several perspective designs were identified, implemented by 3D printing, and showed high characteristics. A linear correlation was found between the strength of the samples and the minimum angle and minimum bond length in the simplified crystal structures. A new cellular geometry with reinforcement struts and increased strength was discovered. This property was found by us independent of the other works, in which the cellular structures were developed by an explicit method. Thus, the developed approach holds perspective for the design of new cellular structures with increased characteristics and for the prediction of their properties.

Engineering biomaterials to 3D-print scaffolds for bone regeneration: practical and theoretical consideration

There are more than 2 million bone grafting procedures performed annually in the US alone. Despite significant efforts, the repair of large segmental bone defects is a substantial clinical challenge which requires bone substitute materials or a bone graft. The available biomaterials lack the adequate mechanical strength to withstand the static and dynamic loads while maintaining sufficient porosity to facilitate cell in-growth and vascularization during bone tissue regeneration. A wide range of advanced biomaterials are being currently designed to mimic the physical as well as the chemical composition of a bone by forming polymer blends, polymer-ceramic and polymer-degradable metal composites. Transforming these novel biomaterials into porous and load-bearing structures via three-dimensional printing (3DP) has emerged as a popular manufacturing technique to develop engineered bone grafts. 3DP has been adopted as a versatile tool to design and develop bone grafts that satisfy porosity and mechanical requirements while having the ability to form grafts of varied shapes and sizes to meet the physiological requirements. In addition to providing surfaces for cell attachment and eventual bone formation, these bone grafts also have to provide physical support during the repair process. Hence, the mechanical competence of the 3D-printed scaffold plays a key role in the success of the implant. In this review, we present various recent strategies that have been utilized to design and develop robust biomaterials that can be deployed for 3D-printing bone substitutes. The article also reviews some of the practical, theoretical and biological considerations adopted in the 3D-structure design and development for bone tissue engineering.