No abstract

Considerable effort has been made to model, predict, and mitigate wear as it has significant global impact on the environment, economy, and energy consumption. This work proposes generalized foundation-based wear models and a simulation procedure for single material and multimaterial composites subject to rotary or linear abrasive sliding wear. For the first time, experimental calibration of foundation parameters and asymmetry effects are included. An iterative wear simulation procedure is outlined that considers implicit boundary conditions to better reflect the response of the whole sample and counter-body system compared to existing models. Key features such as surface profile, corresponding contact pressure evolution, and material loss can be predicted. For calibration and validation, both rotary and linear wear tests are conducted on purpose-built tribometers. In particular, an experimental calibration procedure for foundation parameters is developed based on a Levenberg–Marquardt optimization algorithm. This procedure is valid for specific counter-body and wear systems using experimentally measured steady-state worn surface profiles. The calibrated foundation model is validated by a set of rotary wear tests on different bimaterial composite samples. The established efficient and accurate wear simulation framework is well suited for future design and optimization purposes.

No abstract

No abstract

Purpose Mechanical anisotropy associated with material extrusion additive manufacturing (AM) complicates the design of complex structures. This study aims to focus on investigating the effects of design choices offered by material extrusion AM – namely, the choice of infill pattern – on the structural performance and optimality of a given optimized topology. Elucidation of these effects provides evidence that using design tools that incorporate anisotropic behavior is necessary for designing truly optimal structures for manufacturing via AM. Design/methodology/approach A benchmark topology optimization (TO) problem was solved for compliance minimization of a thick beam in three-point bending and the resulting geometry was printed using fused filament fabrication. The optimized geometry was printed using a variety of infill patterns and the strength, stiffness and failure behavior were analyzed and compared. The bending tests were accompanied by corresponding elastic finite element analyzes (FEA) in ABAQUS. The FEA used the material properties obtained during tensile and shear testing to define orthotropic composite plies and simulate individual printed layers in the physical specimens. Findings Experiments showed that stiffness varied by as much as 22% and failure load varied by as much as 426% between structures printed with different infill patterns. The observed failure modes were also highly dependent on infill patterns with failure propagating along with printed interfaces for all infill patterns that were consistent between layers. Elastic FEA using orthotropic composite plies was found to accurately predict the stiffness of printed structures, but a simple maximum stress failure criterion was not sufficient to predict strength. Despite this, FE stress contours proved beneficial in identifying the locations of failure in printed structures. Originality/value This study quantifies the effects of infill patterns in printed structures using a classic TO geometry. The results presented to establish a benchmark that can be used to guide the development of emerging manufacturing-oriented TO protocols that incorporate directionally-dependent, process-specific material properties.