Study Examines Compressive Behavior of 3D Printed Lattice Structures

Share this Article

Lattice structures are frequently found in additive manufacturing, as their complex forms are easy to make using 3D printing. The technology also makes it possible to construct them from multiple materials. Because of their high specific strength and stiffness, lattice structures are often used in the aerospace, defense and automotive industries. In a paper entitled “Compressive Behavior of Strut Reinforced Kagome Structures Fabricated by Fused Deposition Modeling,” a group of researchers investigates the compressive performance of modified Kagome unit cells.

Kagome is a type of lattice structure defined by the researchers as “a stretch dominated 3D truss structure derived from the design pattern of a woven basket.” A modified version of Kagome structure is strut reinforced Kagome (SRK), which has been shown to have better compressive properties than standard Kagome. For the study, the researchers used ABS to 3D print SRK structures.

“Uniaxial compression tests were carried out in Shimadzu Universal Testing Machine using 10 kN load-cell, and compression load was applied under displacement control at a rate of 0.1 mm/min,” the researchers explain. “Video extensometer TRViewX was used to measure the accurate displacement between the faceplates. The engineering stress-strain data are obtained from the measured force (F) and displacement (h). The stress was calculated by dividing the force by the effective area which is obtained in terms of truss length ( l = 2c) 2 3 c2, whereas the strain is obtained by dividing the displacement by the core height.”

The tests showed that the peak strength and effective modulus increase with the decrease in the slenderness ratio. In addition, SRK structures show different failure behavior with the change in the slenderness ratio.

“The core with lowest relative density (d =2.4 mm, h = 35mm) shows the failure within the linear elastic regime,” the researchers continue. “As the slenderness ratio is very high, the struts failed by elastic buckling without any yielding. With the increase in the relative density (d =2.4 mm, h = 25 mm), there is some plastic deformation before reaching the peak strength as shown in the Figure 2. With further increase in relative density (d = 3 mm, h = 25 mm), we can see the significant plastic nonlinearity before reaching the peak strength. The stress gradually decreases with the increase in the strain.”

The vertical struts in all the samples started to deform after substantial compression. Plastic bending of the vertical strut results in the distortion of the upper and lower part of the SRK, leading to the deformation of the slanted struts. Further compression leads to the formation of surface cracks on the tensile side of the strut. With further loading, the cracks open, leading to the bending of the structure, additional cracks on all sides, and eventual softening and collapse of the structure.

“The anisotropic material behavior and the porous nature of FDM printed structure have led to the discrepancies in the numerical and experimental results,” the researchers conclude. “The performance of SRK unit structure can be further improved by the variation in diameter of the slanted and vertical struts to optimize it for a given density.”

Authors of the paper include Rinoj Gautam, Sridhar Idapalapati, and Estella Siew Lee Koh.

Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.

 

Facebook Comments

Share this Article


Related Articles

Materialise Software Used to Optimize Conformal Cooling Tooling Design of 3D Printed Metal Mold for Toy Car

LLNL: Magnetically Responsive Metamaterials Instantly Stiffen 3D Printed Structures



Categories

3D Design

3D Printed Architecture

3D Printed Art

3D printed chicken


You May Also Like

Investigating Lightweight 3D Printed Structures for Sand Casting

3D printing is often used to produce molds for casting. In the case of sand molds, binder jetting is typically used; however, its high costs, due to expensive materials, need...

Finite Element Modeling Used to Study How Defects Can Effect Porosity in 3D Printed Lattice Structures

For applications that require lightweight structures able to maintain stiffness and strength, 3D printed lattice structure are often used. The complex forms are simple to 3D print, and their mechanical...

First Mechanical Properties Tests of 3D Printed Carbon CLIP Lattice Parts

California 3D printing company Carbon, founded in 2013, suddenly hit the scene in 2015 with its innovative Continuous Liquid Interface Production (CLIP) technology, which uses the power of light and oxygen...

3D Bioprinting: Comparing Lattice Scaffolds with Traditional Rectangular Sheets

Bioprinting is not a simple endeavor – if it were, we would likely be transplanting 3D printed organs by now. It’s a delicate process that requires a number of factors...


Training


Shop

View our broad assortment of in house and third party products.

Subscribe To Our Newsletter

Subscribe To Our Newsletter

Join our mailing list to receive the latest news and updates from our 3DPrint.com.

You have Successfully Subscribed!