Comparative analysis of mechanical properties and energy absorption capabilities of functionally graded and non-graded thermoplastic sheet gyroid structures

Abstract

Comparative analysis of mechanical properties and energy absorption capabilities of functionally graded and non-graded thermoplastic sheet gyroid structuresAdditive manufacturing allows the tailoring of the structure of energyabsorbing materials. It is thus feasible now to use light, printed structures instead of other materials such as foams and honeycombs, signifying greater possibilities for customization. Some of these structures are triply periodic minimal-surface structures that is a family of different structures like the gyroid one. Another benefit of additively manufactured graded structures, which foams or honeycombs lack, is the flexibility to vary the internal parameters along one or more directions. This study focuses on the comparative analysis of graded and non-graded gyroid structures for four common thermoplastic materials used in additive manufacturing.These structures are compared with each other under quasi-static compression testing, as well as with expanded polystyrene foam and solid samples of the thermoplastic materials. The analysis includes investigation of the stress-strain and specific stress-strain curves, capability of absorbing energy per unit weight and per unit volume, ideality, total efficiency, and normalized energy vs. normalized stress characteristics.We also analyze the internal fracture mechanism of the structures. The objective is to obtain more extensive knowledge of the behavior of nongraded structures.

Mechanical properties of diamond lattice structures based on main parameters and strain rate

“…Mechanical tests were repeated 3 times for all volume fractions cell sizes and strain rates. Only small deviation of the results were observed in the stress strain curves as confirmed by the groups previous studies [10,17,32,33] (a selection of some of the results of the study of the variability are shown in Table 1). The low deviation could be due to aspects such as the control of the temperature of the room and of the printing space, the use of the same roll of material for the identical specimens, the use of the same printing machine and that the specimens have been printed and tested consecutively.…”

“…These mechanical properties can be modified by controlling the density during the foaming process [1,2]. Some researchers concluded that this behavior mode applies to corks and cork products [10] and lattice structures [17].…”

“…This technique enables the application of different materials, such as renewable materials like acrylonitrile styrene acrylate (ASA), to produce multimaterial structures [14]. It also possibilities the use different structures based on the zone with different mechanical properties and stiffness [15], modified thickness of the structure based on the zone [16], or the possibility to form gradient structures [17]. Consequently, different methods are used to generate zones with different mechanical properties tailored and optimized, for instance, in the case of helmets, to improve safety and reduce the weight Different types of filling structures can be applied.…”

Mechanical Behavior of Closed-Cell Ethylene-Vinyl Acetate Foam under Compression

“…Energy absorption diagrams are used to evaluate the optimal energy absorption capacity of cushioning packaging materials with different densities at different strain rates under a certain stress level. In cushioning packaging design, through energy absorption diagrams, the geometric dimensions and the most suitable density of cushioning materials can be optimized and chosen [20,23]. So, it is very valuable to draw the energy absorption diagrams of closed-cell EVA foams for cushioning packaging optimization design.…”

Energy Absorption Capability of Graded Hybrid Triply Periodic Minimal Surface Structures Based on Fracture Zone Controlling

“…To further exploit the advantages of the energy absorption capability of the lattice structure, many researches have carried out gradient design on the lattice structures, such as sheet‐based G, [ 16 ] sheet‐based P [ 17 ] and face‐centered cubic (FCC). [ 18 ] Gao et al [ 19 ] conducted linear and nonlinear gradient design for BCC structure with the same relative density.…”