1. Mechanical characterization and constitutive modeling of additively-manufactured polymeric materials and lattice structures.
- Author
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Guo, Xiao, Wang, Erdong, Yang, Hang, and Zhai, Wei
- Subjects
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POISSON'S ratio , *BODY centered cubic structure , *YIELD surfaces , *MODULUS of rigidity , *ELASTICITY - Abstract
• A unified printing angle-dependent constitutive model of base materials is proposed. • Both experimental and numerical results of lattices demonstrate anisotropic mechanical response. • Unit-cell and multi-cell numerical models are established to reveal elastic and initial yield mechanical characteristics of lattices. • The multiaxial yield surface of the lattices, except for the isotropic principal stress plane, can be properly depicted by the extended-hill anisotropic yield criterion. Additively manufactured polymeric lattice structures are being extensively studied, primarily because their mechanical properties can be tailored by controlling the unit cell geometry, giving them higher designability than stochastic materials. However, the inherent layer-wise additive manufacturing process affects the base material properties related to the printing direction, which in turn affects the macroscopic responses of the entire lattice materials. A robust understanding and modeling of lattice structures' elastic and plastic yield behavior in a homogenized approach are essential to enhance their design and analysis efficiency in engineering applications. In pursuit of this goal, a unified printing angle-dependent constitutive model of base materials is proposed in line with the tensile experimental data. The elastic material properties (elastic modulus, shear modulus, and Poisson's ratio), obtained through numerical simulations of one unit-cell with periodic boundary conditions, exhibit anisotropic properties, with the degree of anisotropy determined by the angle of the constituent members and base materials. Furthermore, both experimental and numerical results of lattices demonstrate anisotropic mechanical response under horizontal and vertical compression. Virtual multiaxial experiments are conducted through multi-cell numerical simulations, enabling the determination of initial yielding points of two different lattice structures (Kelvin and Simple cubic and body-centered cubic hybrid structures) under various loading conditions using a dissipation energy-based criterion. Overall, the multiaxial yield surface of the investigated lattices under various stress states, except for the isotropic principal stress plane, can be properly depicted by the Extended-Hill anisotropic yield criterion. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
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