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Lecture

Characterization of the Sandwich Beam With Triply Periodic Minimal Surface Lattice Structures As Core

Thursday (08.10.2020)
14:20 - 14:40

The triply periodic minimal surface lattice structures are function based topologies which also can be observed in nature. Due to their tunable permeability and high surface-to-volume ratio, the structures are introduced to tissue engineering as porous scaffolds for orthopedic applications.

In this work, the potential of applying these structures in lightweight design are investigated. Two types of lattice structures (known as Gyroid and Primitive) based on triply periodic minimal surface are produced by polymer additive manufacturing and laminated with glass fiber fabric. The finished sandwich beams have been examined by four-point bending test. The results indicated that the bend strength of the sandwich beam reduces nearly linearly while the void fraction of the lattice core rises from 0.35 via 0.5 to 0.65. In the region of low void fraction, the bend strength of the sandwiches with Gyroid and Primitive core are close to each other. However, while the void fraction reaches 0.65 the bend strength of sandwich with Gyroid core is three times higher than its with Primitive core. During the tests, all samples with low void fraction are observed with failure of the adhesive bond between core and composite sheets, while in the region of high void fraction, the samples tend to fail because of cracks in core.

This work has proved that the specific mechanical resistance of the sandwich with Gyroid core is significantly better compared to the sandwich with open-cell voronoi foams. Since the mechanical properties of Gyroid structure are easy to be adjusted by changing parameters of its geometry function, the Gyroid structure is very capable of lightweight design.

Speaker:
Yuhao Wang
Karlsruhe University of Applied Sciences
Additional Authors:
  • Prof. Dr. Frank Pöhler
    Karlsruhe University of Applied Sciences