Hexagonal Honeycomb Research Articles

Novel hierarchical bioinspired cellular structures with enhanced energy absorption under uniaxial compression

Biological thin-walled cellular structures, such as hierarchical structures of bone, exhibit unique internal structures that offer lightweight characteristics and high energy absorption capabilities. The compact bone shell can protect against local damage during high-impact events, while the porous cancellous bone is essential in absorbing energy. This research proposed five novel bioinspired cellular structures inspired by the well-arranged structure of femur bones. These structures comprise four distinct cell types: hexagonal honeycomb, re-entrant, hybrid, and hierarchical hybrid cells. A comprehensive numerical model, validated with experimental data, was employed to assess the performance of these structures under uniaxial compression. Some key characteristics were revealed, including peak elastic load, plateau load, energy absorption capacity, Poisson's ratio, and the effect of hierarchical cell size. The results demonstrated that the novel bioinspired structures surpassed the energy absorption performance of traditional designs, such as hexagonal design, re-entrant, and trabecular-bone-inspired structures. This enhanced performance was due to the progressive buckling and collapse mechanisms, showing promising implications for future engineering applications, particularly where energy absorption is of paramount importance.

C, Ge-doped h-BN quantum dot for nano-optoelectronic applications

Emerging materials, particularly nanomaterials, constitute an enduring focal point of scientific inquiry, with quantum dots being of particular interest. This investigation is centered on elucidating the exceptional structural, electromagnetic, and optical characteristics of hexagonal boron nitride (h-BN) quantum dots and h-BN quantum dots doped with carbon (C) and germanium (Ge). The employed methodology in this study hinges on density functional theory coupled with the Vienna Ab initio simulation package. The outcomes of this research unveil the structural stability of hexagonal honeycomb structures upon optimization. Comprehensive examinations encompassing structural properties, electromagnetic characteristics, and charge density variations have been systematically conducted. Furthermore, this work delves into the elucidation of multi-orbital hybridizations that give rise to σ bonds and π bonds. Notably, the outcomes of the optical property analysis divulge intriguing observations. Specifically, the absorption coefficient exhibits zero values within select energy ranges within the visible light spectrum, a phenomenon observed in both pristine and C-doped configurations. This discovery underscores the material’s optical transparency at these specific radiation energies. Additionally, the 0x and 0y components of the dielectric function display negative values across particular energy ranges, a characteristic that holds significant promise for potential applications in nanotechnology communications, offering minimal energy loss.

Design and mechanical properties analysis of hexagonal perforated honeycomb metamaterial

Hexagonal perforated honeycomb (HPH) metamaterials were designed, fabricated and investigated in this work. Initially, the mechanical properties and deformation modes of various proposed HPH metamaterials (HPH-U, HPH-1 L and HPH-3 L) under quasi-static vertical compression were analyzed using experimental and finite element methods. The findings reveal significant improvements in mechanical properties and energy absorption due to the honeycomb and hierarchical expandable design. Notably, the auxetic effect is diminished. Subsequently, the impact of key dimensional parameters on the mechanical properties and Poisson's ratio behavior was explored. The results highlighted that an increase of elliptical perforation major axis to minor axis ratio enhanced the auxetic effect but compromised load-bearing and absorptive capacity. Additionally, HPH metamaterials displayed exceptional performance under quasi-static horizontal compression, with their honeycomb structure enabling them to withstand both vertical and horizontal impacts while exhibiting excellent energy absorption capabilities. The study also identified relative density as a crucial factor influencing horizontal impact performance. Finally, the study subjected the HPH metamaterials to multiple quasi-static vertical repetitive compressions, meticulously analyzing variations in mechanical properties under diverse compression ratios. Due to distinctive structural design and impressive mechanical properties, HPH metamaterials demonstrate immense potential for applications in automotive engineering and sports protection fields.

Effect of 3D-Printed Honeycomb Core on Compressive Property of Hybrid Energy Absorbers: Experimental Testing and Optimization Analysis.

This paper presents an innovative method of constructing energy absorbers, whose primary function is to effectively transform kinetic energy into strain energy in events with high deformation rates. Hybrid specimens are proposed considering thin-walled windowed metallic tubes filled with 3D-printed hexagonal honeycombs made of PET-G and ABS thermoplastic. The patterned windows dimensions vary from 20 × 20, 20 × 30, 15 × 20 and 15 × 30 mm2. Although using polymers in engineering and thin-walled sections is not new, their combination has not been explored in this type of structure designed to withstand impacts. Specimens resist out-of-plane quasi-static axial loading, and test results are analyzed, demonstrating that polymer core gives the samples better performance parameters than unfilled samples regarding energy absorption (Ea), load rate (LR), and structural effectiveness (η). An optimization procedure using specialized software was applied to evaluate experimental results, which led to identifying the optimal window geometry (16.4 × 20 mm2, in case) and polymer to be used (ABS). The optimized sample was constructed and tested for axial compression to validate the optimization outcomes. The results reveal that the optimal sample performed similarly to the estimated parameters, making this geometry the best choice under the test conditions.

Biomimetic Study of a Honeycomb Energy Absorption Structure Based on Straw Micro-Porous Structure.

In this paper, sorghum and reed, which possess light stem structures in nature, were selected as biomimetic prototypes. Based on their mechanical stability characteristics-the porous structure at the node feature and the porous feature in the outer skin- biomimetic optimization design, simulation, and experimental research on both the traditional hexagonal structure and a hexagonal honeycomb structure were carried out. According to the two types of straw microcell and chamber structure characteristics, as well as the cellular energy absorption structure for the bionic optimization design, 22 honeycomb structures in 6 categories were considered, including a corrugated cell wall bionic design, a modular cell design, a reinforcement plate structure, and a self-similar structure, as well as a porous cell wall structure and gradient structures of variable wall thickness. Among them, HTPC-3 (a combined honeycomb structure), HSHT (a self-similar honeycomb structure), and HBCT-257 (a radial gradient variable wall thickness honeycomb structure) had the best performance: their energy absorption was 41.06%, 17.84%, and 83.59% higher than that of HHT (the traditional hexagonal honeycomb decoupling unit), respectively. Compared with HHT (a traditional hexagon honeycomb decoupling unit), the specific energy absorption was increased by 39.98%, 17.24%, and 26.61%, respectively. Verification test analysis revealed that the combined honeycomb structure performed the best and that its specific energy absorption was 22.82% higher than that of the traditional hexagonal structure.

4D printed zero Poisson’s ratio metamaterials with vibration isolation properties for magnetic response

Although mechanical metamaterials possess high specific energy absorption, they suffer from drawbacks such as irreversible deformations and non-adjustable mechanical properties. Magnetic excitation is considered to be one of the most promising methods for special working environments; for which uniform incorporation of UV-cured four-dimensional (4D) printed resin is considered to be an effective approach to achieving fine structural features. Our study investigated the impact of soft magnetic particle content on the mechanical and dynamic mechanical properties of a shape memory polymer matrix material. This paper presents a 4D printed metamaterial with a zero Poisson’s ratio that can sense magnetic field intensity and alter its mechanical properties. Its rapid shape recovery, achieved through magnetic excitation, enables multiple energy absorption within a short timeframe. By increasing the curvature radius, the stress concentration in the hexagonal honeycomb structure is reduced, ensuring the metamaterial maintains its zero Poisson’s ratio even under in-plane loading. The study investigates the energy absorption performance and force–displacement curve of metamaterials with different layers and cell sizes, focusing on a four-layer metamaterial for the analysis. Furthermore, the paper explores the tunable energy absorption characteristics of the four-layer metamaterial under time-varying electromagnetic fields, aiming to enhance the stability of a lander’s center of gravity while landing on uneven terrain.

Design and low-velocity impact behavior of an origami-bellow foldcore honeycomb acoustic metastructure

The ancient art of origami has inspired the design and fabrication of numerous acoustic and energy-absorption mechanical metamaterials and metastructures. This study introduces an origami-inspired honeycomb acoustic metastructure designed for engineering applications that demand both high impact resistance and effective sound absorption. This acoustic metastructure is formed by bonding a panel containing periodically distributed perforated holes and a panel without perforations to a periodical array of trapezoidal origami-bellow units. Acoustic wave propagation and drop-weight impact simulations are conducted to investigate the acoustic performance and low-velocity impact behavior of the metastructure. The results show that the origami-bellow honeycomb structure exhibits superior sound absorption capacity over two frequency ranges, outperforming the conventional honeycomb-core sandwich structure. Furthermore, it is shown that, in comparison with both the conventional hexagonal honeycomb-core and the Miura-ori foldcore sandwich structures, the proposed acoustic metastructure demonstrates higher levels of impact resistance and energy absorption capacity. We also show that the mechanical performance of the introduced metastructure under low-velocity impact loads can be further enhanced by increasing the story height of the origami-bellow units. Besides, the matrix material of the origami foldcore can be tailored to suit various scenarios, providing noise control and collision robustness for a diverse range of engineering applications.

Study on the mechanical properties of cylindrical mechanical metamaterials with biomimetic honeycomb units of the diabolical ironclad beetle

In the long process of evolution in nature, the elytra of the diabolical ironclad beetle are connected in a jigsaw way, so that the overall structure of the beetle has strong pressure resistance. The study of the geometric features and interlocking effect of elytra junctions provides new ideas for the development of new bionic applications. The honeycomb structure is a new type of material structure with excellent mechanical properties, and has broad application prospects in building structure, aerospace and other aspects. Through the reasonable design and modification of the honeycomb structure, the honeycomb structure has different characteristics. Based on the concave hexagonal honeycomb structure, combined with the geometric characteristics of the diabolical ironclad beetle jigsaw connection, the concave hexagonal honeycomb structure is redesigned, and a new type of bionic honeycomb structure is proposed. Through the combination of experiments and simulations, the mechanical response of the bionic honeycomb structure of diabolical ironclad beetles was studied. Research has shown that as the connection angle increases, the curvature on both sides of the unit also increases, making the units more compact. The overall structure exhibits two types of mechanical responses under compression: "U" and "Γ". The structure with connection angle of 25° can rely on the support and buckling on both sides of the unit, thus having the best energy absorption characteristics. As the axial ratio of the ellipse (a:b) increases, the degree of concavity in the structural unit continues to deepen, resulting in three forms of deformation of the structural unit. The structural unit changes from being supported on both sides to being bent on both sides, resulting in a stacking phenomenon in structures with ratios of 2.2:1 and 2.4:1, and the overall structure has better deformation resistance.

Out-of-plane engineering constants of beetle elytra inspired sandwich cores

The Beetle Elytron Plate (BEP) is a new type of biomimetic sandwich core developed as a potential replacement of classical honeycomb cores in sandwich panels. This work investigates the out-of-plane engineering elastic constants, including Young's and pure shear moduli of parametric BEP cellular topologies. The BEP core configurations are simulated using Finite Element models, with both full-scale and representative unit cells for asymptotic homogenization. The numerical models are also validated by flatwise compression and out-of-plane pure shear loading experiments performed according to ASTM standards. The benchmarked models are then used to perform a parametric analysis of the beetle elytra cellular cores against their geometry characteristics. Results show that the out-of-plane Young's modulus E3/Esand the transverse pure shear modulus G31/Es of both BEP configurations are larger than those of the classic hexagonal honeycombs and increase when the size of the unit cell cylinders, or rib thickness become large. The specific shear moduli of the beetle-elytra inspired honeycombs are however lower than those of classical pure hexagonal honeycomb configurations, although the added presence of cylinders within the cell configuration offers opportunities for tailoring the design of multifunctional cores.

VAM-based equivalent-homogenization model for 3D re-entrant auxetic honeycomb structures

The integration of two vertically crossed re-entrant honeycombs gives rise to a 3D re-entrant honeycomb (3D-RH), which displays intricate three-dimensional auxeticity. To simplify the modeling complexity, this study employs asymptotic analysis of the energy functional stored in the unit cell of the 3D-RH to develop unified constitutive models for 3D structures and panels with multiple length scales. Based on this, an equivalent 3D Cauchy continuum model is established for multi-layer 3D-RH, while a 2D equivalent plate model is developed for sandwich panel with single-layer 3D-RH (SP-3D-RH). The accuracy and effectiveness of these equivalent models are subsequently confirmed through investigations of the X-shaped compressive deformation of multi-layer 3D-RH, as well as the in-plane auxetic deformation and out-of-plane dome-shaped deformation of single-layer 3D-RH. Compared to traditional hexagonal and re-entrant honeycomb sandwich panels, the SP-3D-RH exhibited enhanced equivalent tensile stiffness while effectively mitigating maximum deformation and strain energy under bending and tension conditions. However, due to its relatively low equivalent shear stiffness, the SP-3D-RH exhibited significant deformation and strain energy when subjected to torsional loads, resulting in local stress concentration in the connect region between adjacent facesheets. Parameter analysis shows that the facesheet-to-strut thickness ratio had a substantial impact on the equivalent stiffness and in-plane behavior of the SP-3D-RH, while adjusting the horizontal strut length, strut depth, and re-entrant angle of the 3D-RH can improve the out-of-plane behavior.

Enhancing Heat Storage Cooling Systems via the Implementation of Honeycomb-Inspired Design: Investigating Efficiency and Performance

This study presents a novel approach inspired by the hexagonal honeycomb structure found in nature, leveraging image processing algorithms to precisely define complex geometries in thermal systems. Hexagonal phase change material containers and thermally conductive fins were meticulously delineated, mirroring the intricate real-world designs of honeycombs. This innovative methodology not only streamlines setup processes but also enhances our understanding of melting dynamics within enclosures, highlighting the potential benefits of biomimetic design principles in engineering applications. Two distinct honeycomb structures were employed to investigate their impact on the melting process within cavities subject to heating from the left wall, with the remaining walls treated as adiabatic surfaces. The incorporation of a thermally conductive fin system within the enclosure significantly reduced the time required for a complete phase change, emphasizing the profound influence of fin systems on thermal design and performance. This enhancement in heat transfer dynamics makes fin systems advantageous for applications prioritizing precise temperature control and expedited phase change processes. Furthermore, the critical role of the fin system design was emphasized, influencing both the onset and location of the final point of melting. This underscores the importance of tailoring fin systems to specific applications to optimize their performance. Our study highlights the significant impact of the Rayleigh (Ra) number on the melting time in a cavity without fins, revealing a decrease from 6 to 0.4 as the Ra increased from 102 to 105; the introduction of a fin system uniformly reduced the melting time to Ste.Fo = 0.5, indicating fins’ universal effectiveness in optimizing thermal dynamics and expediting the melting process. Moreover, the cavity angle was found to significantly affect the fluid fraction diagram in unfanned cavities but had minimal impact when fins were present, highlighting the stabilizing role of fins in mitigating gravitational effects during melting processes. These insights expand our understanding of cavity geometry and fin interactions in heat transfer, offering potential for enhanced thermal system designs in various engineering applications. Decreasing thermal conductivity (λ) by increasing the fin thickness can halve the melting time, but the accompanying disadvantages include a heavier system and reduced energy storage due to less phase change material, necessitating a careful balance in decision-making.

Prediction of mechanical response of hexagonal honeycomb SPS blast wall under explosive loading: In-depth review and empirical formula

Despite comprehensive prevention strategies, offshore operations consistently grapple with health, safety, and environmental (HSE) challenges. Though explosions on offshore structures are rare, their devastating impact cannot be understated. Blast walls, functioning as pivotal passive barriers, play a crucial role in protecting the topsides of these structures by dissipating explosive energy. Sandwich panel structures (SPS), with their lightweight attributes, enhanced bending rigidity and exceptional energy absorption, are a cost-effective countermeasure. This study introduces a groundbreaking design guideline, anchored in the LS-Dyna nonlinear finite-element method (NLFEM), tailored for hexagonal SPS offshore blast walls under explosive strains. Our rigorous numerical simulations, encompassing 450 varied scenarios, meticulously evaluated an array of geometric configurations and explosive strengths (spanning from 1 kg to 3 kg of TNT). From these simulations, crucial parameters affecting maximum mid-span plate deflection were discerned. In addition to these simulations, our research offers in-depth technical reviews, shedding light on the nuances of the subject. An empirical formula was subsequently formulated to anticipate this deflection, corroborating its efficacy by FE simulation outcomes. This work provides invaluable guidance for refining early-stage offshore blast wall design.

A 2D low-buckled hexagonal honeycomb Weyl-point spin-gapless semiconductor family with the quantum anomalous Hall effect.

Spin-gapless semiconductors (SGSs), serving as superior alternatives to half-metals, open up new avenues in spintronics. Specifically, Weyl-point SGSs (WPSGSs) with ideal Weyl points at the Fermi energy level represent an optimal amalgamation of spintronics and topological physics. Moreover, considering spin-orbital coupling (SOC), most two-dimensional (2D) WPSGSs undergo transformation into half Chern insulators (HCIs) with the emergence of the quantum anomalous Hall effect (QAHE). The 2D I-II-V half-Heusler compounds, constituting a broad family of narrow-bandgap semiconductors with low-buckled hexagonal honeycomb crystal structures akin to silicene, aptly function as SGSs and serve as nontrivial topological parent materials. Through first-principles calculations, we propose that the Li12X10Cr2Y12 (X = Mg, Zn, Cd; Y = P, As) monolayers, derived by substituting certain X atoms in the LiXY (X = Mg, Zn, Cd; Y = P, As) monolayers of I-II-V half-Heusler compounds with Cr atoms, emerge as potential candidates for ideal 2D WPSGSs. These monolayers exhibit stable thermodynamic properties and 100% spin polarization. With SOC taken into account, the Li12X10Cr2Y12 monolayers transition into HCIs with a Chern number of +1, giving rise to the QAHE. These intriguing findings lay the groundwork for a promising material platform for the development of low-power spintronic and topological microelectronic devices.

Droplet tilings in precessive fields: hysteresis, elastic defects, and annealing.

Two-component Marangoni contracted droplets can be arranged into arbitrary two-dimensional tiling patterns where they display rich dynamics due to vapor-mediated long-range interactions. Recent work has characterized the centered hexagonal honeycomb lattice, showing it to be a highly frustrated system with many metastable states and relaxation occurring over multiple timescales [Molina et al., Proc. Natl. Acad. Sci. U. S. A., 2021, 118, e2020014118]. Here, we study this system under the influence of a rotating gravitational field. High amplitudes are able to completely disrupt droplet-droplet interactions, making it possible to identify a transition between field-dominated and interaction-dominated regimes. The system displays complex hysteresis behavior, the details of which are connected to the emergence of linear mesoscale structures. These mesoscale features display an elasticity that is governed by the balance between gravity and long-range vapor-mediated attractions. We find that disorder plays an important role in determining the dynamics of these features. Finally, we demonstrate annealing the system by progressively reducing the field amplitude, a process that reduces configurational energy compared to a rapid quench. The ability to manipulate vapor-mediated interactions in deliberately designed droplet tilings provides a novel platform for table-top explorations of multi-body interactions.

Experiment and finite element analysis of protective honeycombs based on equivalent method for ocean engineering under impact loading

Aiming at reducing damage between ship berthing and high-pressure vessels, the protective honeycomb filled with Roller Arrowhead Wings Honeycomb (RAWH) was constructed based on equivalent method. A novel Double Arrowhead Wings Honeycomb (DAWH), inspired by Tilia Platyphylloswas, was proposed for arrangement in RAWH. The analytical models were derived with size factor n for honeycomb selection and design. The mechanical properties, energy absorption, compression response, structure efficiency, and deformation mode of RAWH were investigated by Finite Element Analysis (FEA) and Experiment (EXP), comparing with Roller Hexagonal Honeycomb (RHH), Roller Re-entrant Honeycomb (RRH), and Roller Solid. With particular calculation methods, the work energy absorption, engineering strain, and engineering stress were obtained within acceptable error compared to finite element analysis. The contact force of RAWH exceeded RHH, RRH and Solid about 1.7, 5, and 0.32 times, with a maximum of 15000 N. Further, the deformation modes of RAWH were discussed and recorded with “V” mode and “U” mode appearing special characteristics of enhancement and resilience. The equivalent Poisson’s ratios for protective honeycombs were studied and described in the Morgan-Mercer-Flodin (MMF) growth model with the phenomena of “Step Fluctuation”, “Inter-layer Progression” and “Step Stability”. These results, methods, and discussions might bring significance for reducing damage from collisions in ocean engineering.

Kirigami-inspired organic and inorganic film-based flexible thermoelectric devices with built-in heat sink

Thermoelectric (TE) devices can convert heat to electricity directly, which offers a unique opportunity to realize waste heat recovery. However, conventional TE devices inevitably use heat sinks, which are bulky, rigid and heavy, limiting practical applications. Herein, we propose a fully integrated film-based TE device with intrinsically built-in fins as heat sink in a hexagonal honeycomb device structure, that simultaneously achieves high TE performance and conformability, as confirmed by experiments and modelling. A flexible Kapton substrate with copper electrodes, integrating either carbon nanotube (CNT) veils or bismuth telluride (Bi2Te3) TE ‘legs’, both of n- and p-type, achieved a remarkable specific power of 185.4 nW K−2 for a Bi2Te3-based device and 53.1 nW K−2 for a CNT-based device, thanks to the heat dissipation effect granted by the built-in fins. Besides, the addition of oriented polymer films interconnects, contracting when above their glass transition temperature, allowed a single substrate two-dimensional (2D) TE device to self-fold into a three-dimensional (3D) hexagonal honeycomb structure, with built-in fins, contactlessly and autonomously. The demonstrated shape-programmed kirigami-inspired scalable TE device paves the way for realising self-powered applications comprising hundreds of TE legs with both inorganic (e.g., Bi2Te3) and organic (e.g. CNT veils) TE materials and integrated heat sinks.

Self-similar hierarchical honeycombs in two different fractal layouts: A comparative study of the in-plane crushing behaviors

This paper provides a new avenue for the development of cellular structures. By mimicking the chemical structural formula of the TpPB-Fe coordination polymer, a new self-similar hierarchical honeycomb was proposed. With respect to the existing self-similar hierarchical honeycomb in the literature which was constructed by replacing every three-edge vertex of the regular hexagonal honeycomb with a smaller hexagon, the new one is created by setting the fractal position at the midpoint of the cell walls of the regular hexagonal honeycomb. What I am really curious about is the difference in mechanical properties between the two self-similar hierarchical honeycombs. Finite element (FE) model was first built and validated by comparing against the existing theoretical data. Subsequently, the in-plane crushing behaviors of the honeycombs under different impact velocities were fully investigated by FE simulations. The deformation modes, plateau stress as well as the energy absorption capability of the honeycombs were studied. Different macroscopic and microscopic deformation patterns between the two hierarchical honeycombs were observed. The plateau stress of the new hierarchical honeycomb is higher than that of both the existing counterpart and the basic regular hexagonal one. Under low- and medium-velocity impact loading, the new honeycomb with low fractal ratio (α) has superior energy absorption capability with respect to the existing counterpart and the basic regular hexagonal one. However, the new honeycomb will lose its advantage in energy absorption when the fractal ratio or the impact velocity is large.

Two-particle quantum walk on graphene structure graph

Graphene, a new material with a hexagonal honeycomb sheet structure composed of a single layer of carbon atoms, is the world's thinnest and strongest substance known to human, it has low resistivity and strong light transmission characteristics, so it can be used as a candidate material for integrated circuit chips and new energy batteries. In this paper, we mainly discuss the quantum walk of two non-interacting particles on the graphene structure graph, in which we select coin operator G in coin space HC and construct shift operator S, the time evolution operator U is obtained from the tensor of G and S. Since two particles without interaction can occupy the same site, the initial state is a composite of two particles at the same site. On this foundation, the relation between the relative distance and evolution time of two non-interacting particles is studied by the distance evolution operator.

Influence of Cell Pore Configuration on Dynamic Mechanical Properties of Honeycomb Structures

With the rapid development of advanced manufacturing technologies such as additive manufacturing, which provides an effective means for processing and preparing a variety of structures with more complex geometrical configurations, the design and study of honeycomb structures have played an important role in promoting the design and study of honeycomb structures. At present, the study of such structures is mainly limited to hexagonal honeycombs, and relatively few studies have been conducted on other cell geometries. In this study, by using the finite element method, we have simulated and investigated the mechanical properties of typical honeycomb structures, in which these structures have different cellular pore configurations and arrangements that are subjected to in-plane low-velocity impact loading. We compared their dynamic load-carrying capacity and deformation patterns with the relative density and impact velocity which is kept constant. Our results show that different cell pore configurations lead to different cell wall stress states during the compression of the honeycomb structure, which affects the macroscopic mechanical properties of the overall structure. Honeycombs with predominantly cell-edge bending have lower stiffness, compressive strength and smoother platform stresses. Honeycombs with deformation modes dominated by cell-wall plastic buckling have the opposite properties. The design of protective structures through further combinatorial optimization of honeycomb structures provides more options to enhance their overall behavior and energy absorption properties.

CO2 reduction of resolved wall structures: A load-bearing capacity-based modularization and assembly approach

The demand for new housing is constantly growing and cannot be met by artisanal, in-situ construction methods. At the same time, CO2 emissions generated from the construction of new buildings need to be significantly reduced. Precast concrete elements offer the potential for an optimized design with minimal material consumption using high-performance materials. However, this only makes sense when the precast modules can be fabricated in a serial manner. Therefore, a modularization approach is developed that resolves structures into a small number of similar modules to enable an efficient and rapid mass production. Walls and wall-like beams are divided into hexagonal honeycomb structures mainly consisting of Y-modules and columns. The load-bearing capacity of these modules is described holistically for bending, shear and stability. By means of clustering, modules with low CO2 emissions with respect to their load-bearing capacity are grouped into construction kits. These kits are then used to assemble the final honeycomb structures. This combinatorial optimization problem is solved with two metaheuristics, Tabu Search and Simulated Annealing. Three case studies show that this modular approach reduces CO2 emissions by up to 80% compared to monolithic structures. The optimized positioning saves a further 23% with the same load-bearing capacity.