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Engineering Science in
Additive Manufacturing Mechanical property of metal-based IPC

A B C

D E F

G H I

Figure 2. Quasi-static compressive results. Representative engineering stress-strain curves for (A-C) truss lattices (with stress distribution at ~0.08
compression strain) and (D-F) IPC metamaterials. (G) Comparison of the compressive strength of IPCs with the linear summation of their individual
components. (H) Comparison of SEA between IPCs and their corresponding truss lattices. (I) Compressive strength and SEA of various metamaterials in
Ashby plot.
Abbreviations: IPC: Interpenetrating phase composite; SEA: Specific energy absorption.

As illustrated in Figure 2A-C, the stress-strain curves for persisting until densification occurs. The plateau behavior
all truss microlattices demonstrate initial linear behavior, signifies the ability of IPC metamaterials to sustain
indicating stable elastic deformation behavior of the compressive loads over a wide strain range, enhancing their
truss lattice. On attaining the peak stress, the truss struts capacity to absorb external energy more effectively. Given
undergo abrupt failure, which results in a sharp drop in the complexity of simulating inter-component interactions
stress. It is followed by a post-failure regime characterized and failure mechanisms within IPC metamaterials, three
with significant stress fluctuations. These fluctuations repeated experimental results for each IPC configuration
signify the instability of the truss lattices driven by are presented to ensure reliability and reproducibility.
localized fracture and collapse during a large deformation. The consistent trends observed across these repeated tests
Notably, similar load drop behaviors are observed in the highlight the robustness of the IPC design.
numerical simulations, validating the experimental results Figure 2G presents a quantitative comparison of the
and confirming the reliability of the FEA. compressive strengths between IPC metamaterials and
However, the engineering stress-strain curves for their constituent components. The compressive strengths
the IPC metamaterials (FCC, FCCR, and FCCH-IPCs) of FCC, FCCR, and FCCH-IPCs metamaterials exceed the
reveal distinct mechanical characteristics, as shown in linear summation of the strengths of their individual truss
Figure 2D-F. Unlike the truss microlattices, the IPC lattices and solid epoxy components by 31.62%, 36.06%,
metamaterials exhibited a smaller stress drop after reaching and 47.93%, respectively. Here, the solid epoxy resin refers
the peak load, transitioning into a progressive collapse to a pure resin cubic specimen without voids reserved for
mode. This mode is characterized by a relatively stable the metal lattice. The following inequality holds in practical
and extended plateau region in the stress-strain curve, comparative scenarios:

Volume 1 Issue 1 (2025) 5 doi: 10.36922/esam.8554