Design and Testing of Scalable 3D-Printed Cellular Structures Optimized for Energy Absorption

At a Glance

Metadata	Details
Publication Date	2017-01-01
Authors	Sagar Dilip Sangle
Institutions	Wright State University
Citations	3
Analysis	Full AI Review Included

Technical Documentation & Analysis: High-Performance Cellular Structures

Executive Summary

This analysis reviews research into optimizing 3D-printed cellular lattice structures for maximum specific energy absorption (SEA), an application critical for lightweight, high-performance sandwich cores in aerospace and impact-sensitive systems.

Research Objective: Identify optimal lattice topologies (specifically the Tetrahedron, Configuration 4) for maximizing energy absorption per unit mass (SEA).
Material Performance Gap: The study utilized ABS polymer (physical testing) and Ti-6Al-4V alloy (FEA simulation). While Ti-6Al-4V achieved an SEA of 1.22E+08 J/kg in simulation, this performance is fundamentally limited by the material’s modulus and density profile.
6CCVD Value Proposition: 6CCVD’s MPCVD Diamond (SCD/PCD) offers a Young’s Modulus (E) significantly higher (up to 10x) than Ti-6Al-4V, combined with low density, positioning it as the ideal material to achieve next-generation, ultra-stiff, and lightweight cellular structures far exceeding the performance ceiling of conventional metals and polymers.
Optimal Topology: The Tetrahedron structure (Configuration 4), a stretch-dominated topology, consistently demonstrated the highest SEA across elastic, elastic-plastic FEA, and physical compression tests.
Manufacturing Solution: Replicating these complex, high-resolution lattice designs in ultra-hard materials requires advanced micro-machining. 6CCVD provides precision laser cutting and etching services necessary to realize these optimized diamond core geometries.

Technical Specifications

The following table summarizes the key material properties used in the Finite Element Analysis (FEA) and the maximum specific energy absorption (SEA) results achieved by the optimal configuration (Tetrahedron, Configuration 4).

Parameter	Value	Unit	Context
Optimal Configuration	Tetrahedron (Config. 4)	Topology	Stretch-dominated lattice structure
FEA Material	Ti-6Al-4V	Alloy	Used for Elastic + Plastic simulation
Young’s Modulus (E)	1.038e5	MPa	Ti-6Al-4V input property
Poisson’s Ratio	0.31	Dimensionless	Ti-6Al-4V input property
Yield Strength	8.27E+08	N/m²	Ti-6Al-4V yield point
Max SEA (FEA)	1.2242E+08	J/kg	Configuration 4 (Ti-6Al-4V, 1mm diameter)
Test Material	ABS Polymer	Polymer	Used for physical compression testing
Max SEA (Test)	5.84E+05	J/kg	Configuration 4 (ABS, 3.63 g mass)
Strut Diameter (D) Tested	0.5 to 1.0	mm	Critical geometric variable
Unit Cell Size (L) Tested	5, 8, 10	mm	Critical geometric variable
Compression Rate (Test)	0.5	mm/min	Quasi-static loading condition

Key Methodologies

The research employed a combined computational and experimental approach to evaluate five distinct cellular lattice topologies for energy absorption capabilities.

Design and Modeling:
- Five configurations were modeled: Diamond (BCC), Diamond with Vertical Struts, Tetra Structure, Tetrahedron, and Pyramid.
- Geometric variables (strut diameter D, unit cell size L/H) were systematically varied to find optimum dimensions.
Finite Element Analysis (FEA):
- Software: SOLIDWORKS (Elastic Analysis) and ANSYS APDL (Elastic + Plastic Analysis).
- Material: Ti-6Al-4V alloy properties were used for high-performance simulation.
- Loading: Quasi-static compression load applied in steps until yield point failure.
Sample Fabrication (3D Printing):
- Method: Fused Deposition Modeling (FDM) using a Stratasys uPrint SE plus 3D printer.
- Material: Acrylonitrile Butadiene Styrene (ABS) polymer.
- Sample Size: 25 mm x 25 mm x 20 mm³ (5x5x4 unit cells).
- Post-Processing: Support material (SR-30 soluble) removed via chemical bath (Wave Wash apparatus).
Compression Testing:
- Equipment: INSTRON 5500 R universal testing machine (150 KN capacity).
- Data Acquisition: Load-displacement curves recorded (up to 15,000 readings) to calculate energy absorbed (Area under the curve) and Specific Energy Absorption (SEA).

6CCVD Solutions & Capabilities

The research highlights the critical need for materials possessing high Young’s Modulus and low density to maximize specific energy absorption in cellular structures. 6CCVD’s MPCVD diamond materials are uniquely positioned to meet and exceed these requirements, enabling the next generation of ultra-lightweight, high-stiffness components for extreme environments.

Applicable Materials for Advanced Cellular Cores

To replicate and significantly extend the performance demonstrated by the optimal Tetrahedron configuration (Configuration 4), 6CCVD recommends the following materials:

Material Grade	Description	Application Relevance
Optical Grade SCD	Highest purity Single Crystal Diamond. E > 1000 GPa.	Ultimate stiffness and thermal management for micro-lattice structures where minimal mass and maximum structural integrity are paramount.
High-Quality PCD	Polycrystalline Diamond plates/wafers up to 125mm.	Ideal for large-scale sandwich panel cores requiring high strength and stiffness over large areas (e.g., aerospace structural components).
BDD (Boron-Doped Diamond)	Electrically conductive diamond.	If the cellular structure requires integrated sensing, heating, or electrochemical functionality alongside structural integrity.

Customization Potential for Lattice Structures

The successful realization of complex, high-performance lattice structures like the Tetrahedron requires micron-level precision in processing ultra-hard materials. 6CCVD’s capabilities directly address the manufacturing limitations encountered in the research (e.g., inability to print struts below 1mm diameter).

Precision Micro-Machining: We utilize advanced laser cutting and etching techniques to define complex 3D geometries and fine features (struts, nodes) in SCD and PCD plates, achieving resolutions far superior to FDM printing.
Custom Dimensions: We supply diamond plates and wafers up to 125mm (PCD) and up to 500µm thick (SCD/PCD), providing the foundational material necessary for large-scale core fabrication.
Ultra-Smooth Polishing: For applications requiring minimal surface defects that could act as stress concentration points (a key failure mode in lattice structures), we offer polishing down to Ra < 1nm (SCD) and Ra < 5nm (Inch-size PCD).
Integrated Metalization: If the final cellular structure requires bonding to face sheets or integration into a hybrid material system, 6CCVD offers in-house metalization services (Au, Pt, Pd, Ti, W, Cu).

Engineering Support

The transition from conventional materials (ABS, Ti-6Al-4V) to high-modulus diamond for energy absorption applications requires specialized expertise. 6CCVD’s in-house PhD team provides comprehensive engineering consultation for projects focused on:

Material selection and optimization for extreme stiffness and specific energy absorption (SEA).
Design for manufacturability (DFM) of complex lattice topologies (e.g., Tetrahedron, Octet) in ultra-hard MPCVD diamond using laser processing techniques.
Thermal and mechanical modeling to predict the performance of diamond cellular structures in high-impact or high-temperature environments (e.g., aerospace shielding).

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Sandwich panel structures are widely used due to their high compressive and flexural stiffness and strength-to-weight ratios, good vibration damping, and low through-thickness thermal conductivity. These structures consist of solid face sheets and low-density cellular core structures that are often based upon honeycomb topologies. Interest in additive manufacturing (AM), popularly known as 3D printing (3DP), has rapidly grown in past few years. The 3DP method is a layer-by-layer approach for the fabrication of 3D objects. Hence, it is very easy to fabricate complex structures with complex internal features that cannot be manufactured by any other fabrication processes. Due to the recent advancement of 3DP processes, the core lattice configurations can be redesigned to improve certain properties such as specific energy absorption capabilities. This thesis investigates the load-displacement behavior of 3D printable lattice core structures of five different configurations and rank them according to their specific energy absorption under quasi-static loads. The five different configurations are body centered cubic (bcc) diamonds without vertical struts; bcc diamonds with vertical alternate struts, tetras, tetrahedrons, and pyramids. First, both elastic and elastic-plastic finite element analysis (FEA) approach was used to find optimum cell dimension for each configuration. Cell size and strut diameter were varied for each configuration, the energy absorption during compression were calculated, and the optimum dimension was identified for each configuration. Next, the optimized designs were printed using acrylonitrile butadiene styrene (ABS) polymer to evaluate their compression behavior. Fused deposition modeling based Stratasys uPrint printer was used for printing the samples. After printing the samples, all five designs of lattice structures were subjected to compression load and their load-displacement behavior were analyzed and compared. From both FEA calculations and experimental results, the five configurations can be placed as tetrahedrons, pyramids, tetras, BCC diamonds with struts, and diamonds without struts, the first one having the highest and the last one having the lowest energy absorption capabilities. A detailed discussion on the FEA modeling, sample fabrication, and testing of different configurations is presented in the thesis report.

Tech Support

Original Source

DOI: None