Compression Torsion Research Articles

Inclined‐Strut Optimized Mechanical Metamaterials with Enhanced Compression–Torsion Conversion Efficiencies

Herein, two improved compression–torsion conversion (CTC) mechanical metamaterials are proposed with arrayed‐type and cylindrical shell‐type based on the optimization design of an inclined strut. Compared with the original design, improvements in CTC performance can be achieved by optimization of the strut shape in the feasible region. The CTC properties of the optimized metamaterials are studied by theoretical calculations, finite‐element simulations, and experiments. The effects of the shape coefficients of the S‐strut on the optimization efficiencies are discussed. The optimized structures significantly improve the mechanical properties of the CTC mechanical metamaterials. The optimized S‐strut metamaterials are increased by more than 25% higher CTC efficiencies than the original structures. The structures have improved CTC properties and are closer to the application. In addition, the proposed S‐strut mechanical metamaterials have a promising application in the aerospace field.

Design and analysis of three-dimensional chiral metamaterials for enhanced torsional compliance

Three-dimensional (3D) chiral structures are a subset of mechanical metamaterials known for their distinctive deformation characteristics, including the presence of auxetic and compression–torsion coupling behaviors. In this study, a novel 3D chiral metamaterial with high torsional compliance was designed. A gammadion-shaped chiral cell comprising inclined ligaments was incorporated into the chiral structure for enhanced torsional compliance. Finite element analyses (FEAs) were performed to demonstrate that the proposed chiral structure outperformed other chiral structures in terms of torsional compliance. Furthermore, FEAs were performed to investigate the influence of the slenderness ratio and ligament diameter of the chiral structure, on attaining a maximum torsional compliance of 18.6° N−1. These 3D chiral structures were fabricated using additive manufacturing techniques, and experimental validations were performed to observe and confirm the compression–torsion coupling behaviors. To further expand the utility of these 3D chiral structures, statistical analyses were conducted to establish regression models for effective density and torsional compliance, as functions of the slenderness ratio and ligament diameter. These regression models can enhance the applicability of the proposed chiral structures in the development of versatile functional components that require compression–torsion coupling behaviors.

Mechanism of Viral DNA Packaging in Phage T4 Using Single-Molecule Fluorescence Approaches.

In all tailed phages, the packaging of the double-stranded genome into the head by a terminase motor complex is an essential step in virion formation. Despite extensive research, there are still major gaps in the understanding of this highly dynamic process and the mechanisms responsible for DNA translocation. Over the last fifteen years, single-molecule fluorescence technologies have been applied to study viral nucleic acid packaging using the robust and flexible T4 in vitro packaging system in conjunction with genetic, biochemical, and structural analyses. In this review, we discuss the novel findings from these studies, including that the T4 genome was determined to be packaged as an elongated loop via the colocalization of dye-labeled DNA termini above the portal structure. Packaging efficiency of the TerL motor was shown to be inherently linked to substrate structure, with packaging stalling at DNA branches. The latter led to the design of multiple experiments whose results all support a proposed torsional compression translocation model to explain substrate packaging. Evidence of substrate compression was derived from FRET and/or smFRET measurements of stalled versus resolvase released dye-labeled Y-DNAs and other dye-labeled substrates relative to motor components. Additionally, active in vivo T4 TerS fluorescent fusion proteins facilitated the application of advanced super-resolution optical microscopy toward the visualization of the initiation of packaging. The formation of twin TerS ring complexes, each expected to be ~15 nm in diameter, supports a double protein ring-DNA synapsis model for the control of packaging initiation, a model that may help explain the variety of ring structures reported among pac site phages. The examination of the dynamics of the T4 packaging motor at the single-molecule level in these studies demonstrates the value of state-of-the-art fluorescent tools for future studies of complex viral replication mechanisms.

A study of deformation mechanisms for a two-dimensional metamaterial

This paper presents a numerical study of a two-dimensional tetrachiral metamaterial and the effect of unit cell parameters on its mechanical behavior. Finite element simulations are performed using independently varied geometric parameters of the chiral unit cell. Chiral structures can induce the compression–torsion effect and the deflection in mechanical metamaterials. The sample deflection is affected by the following factors: ring deformation, ligament deformation, and structure twisting. The highest strain estimated by the deflection of the metamaterial sample from the initial position is observed at an optimal ratio of ligament length to ring size. The effect of structural parameters on the deformation, stress distribution, and effective elastic properties of a two-dimensional metamaterial sample under uniaxial compression is studied and analyzed. For all variable parameters, a qualitatively similar nature of the equivalent stress distribution is revealed. It is found that a decrease in the volume of the main material in the metamaterial sample entails a decrease in effective Young’s modulus. The parameters accounting for the auxetic properties of the metamaterial are obtained. Effective Poisson’s ratio is determined in the range from –0.1 to 0.95.

Influence of Topological Defects on the Mechanical Response of Unit Cells of the Tetrachiral Mechanical Metamaterial

The primary benefit of metamaterials is that their physical and mechanical properties can be controlled by changing the structure geometry. Numerical analysis tools used in this work offer a few advantages over full-scale testing, consisting of an automated process, as well as lower material and time costs. The investigation is concerned with the behavior of unit cells of the tetrachiral mechanical metamaterial under uniaxial compression. The base material is studied within an elastic mathematical model. The influence of topological defects of the unit cell on the metamaterial properties is studied for the first time. Defects, and especially topological defects, play a decisive role in the mechanical behavior of materials and structures. The unit cell without defects reveals orthotropy of properties. Torsion of a cell with a chiral structure is induced by the rotation of all tetrachiral walls, and therefore it is sensitive to the introduction of defects. There are cases of increased torsion as well as of no compression–torsion coupling effect. In the latter case, the unit cell experiences only shear. The effective Young’s modulus is calculated to vary in the range from 23 to 57 MPa for unit cells of different topologies. With the successive introduction of defects in two walls, the studied characteristics increase, correlating with each other. A further increase in the number of defects affects the characteristics in different ways. The introduction of two more defects in the walls decreases torsion and increases Young’s modulus, after which both characteristics decrease. The introduction of topological defects in all walls of the unit cell leads to the orthotropic behavior of the cell with the opposite sign of torsion.

Evaluation of Unicortical Locking Screw Placement for Torsional Loads in Distal Radius Fractures: A Biomechanical Study in Cadavers.

Background We aimed to compare bio-mechanical outcomes of short-length 75%-length uni-cortical screw (SL75UCS) and full-length 100%-lengthscrews (FL100S) under axial compression (AXC) and torsional compression (TRC) in cadaveric distal radius volar plate model. Methodology A total of 20 wrists from 10 fresh frozen cadavers were included. A 2.5 mm titanium alloy distal radius anatomical platewas placed to the distal radii in full anatomical position, just proximal to the watershed line. Three bi-cortical screws to the shaft of the radius, followed by uni-cortical drilling for distal screwing were placed. Measurement by pulling the drill once it reached the opposite cortex was applied. We selected the screw lengths such that they corresponded to the SL75UCS. In the same configuration for each of the cadavers, we delivered six screws from distal radius holes of the anatomical plate. An oscillating handsaw was used to create an extra-articular distal radius fracture model (AO 23-A3.2). We created a dorsal AP model by performing a 1-cm wedge osteotomy from the dorsal aspect. Complete separation of the volar cortex was achieved. Potting was performed by embedding the shaft of the prepared radius into the polyurethane medium. We placed aluminum apparatus into the distal end to ensure applying of AXC and TRC in bio-mechanistic tests. Results No statistically significant difference of stiffness between the SL75UCS and FL100S both under AXC (p=0.88) and TRC (p=0.82). SL75UCSand FL100S groups did not differ in elastic limit under AXC (p=0.71) and TRC (p=0.71). Maximal force on SL75UCSand FL100S groups were also similar under both AXC (p=0.71) and TRC (p=0.50). Conclusions Our study findings suggest that drilling the dorsal cortex may not be necessary in the management of distal radius fractures. Instead, utilizing SL75UCS could serve as a viable alternative. This approach offers potential advantages in reducing the risk of extensor tendon complications associated with drilling or screw protrusion. It is a safe method under torsional load to avoid drilling of the dorsal cortex and SL75UCS could be performed in order to prevent from extensor tendon complications secondary to drilling or screw protrusion.

Cyclic behavior and ultimate bearing capacity of circular concrete-filled double skin steel tube members subjected to combined compression and torsion

This paper presents a pseudo-static test investigation and finite element analysis on the behavior of circular concrete-filled double skin steel tube (CFDST) members under axial compression and torsion. The hollow ratio (χ) and axial compression ratio (n) are considered in the test study. The ductility, hysteretic behavior, failure modes, and compression–torsion correlation of circular CFDST members are discussed. The comparison results show that the validated finite element model is capable to capture the behavior of circular CFDST members under compression and torsion. The effect of loading paths and various parameters on the compression–torsion correlation of circular CFDST members are analyzed. Parametric analyses are carried out to investigate the effect of key parameters, such as material properties, nominal steel ratio, the wall thickness of inner steel tube, and hollow ratio on the compression–torsion correlation of circular CFDST members. It can be seen that the circular CFDST members under compression and torsion possess good load-bearing capacity, energy dissipation, and ductility properties. The loading paths, yield strength of inner and outer steel tubes, nominal steel ratio, and the wall thickness of inner steel tubes have little effect on the compression–torsion correlation of the composite members. When the axial compression ratio is less than 0.2, the axial compression load can slightly improve the torque capacity of circular CFDST members. Finally, the compression–torsion correlation equation of these members was proposed by regression analysis, and design formulas with good accuracy for predicting the torque capacity of circular CFDST members under compression and torsion were proposed.

Structural evolution characteristics and genesis of buried hill faults in the Chengdao–Zhuanghai area

The buried hills in the Chengdao–Zhuanghai area are rich in oil and gas resources, and their structures exhibit complex styles with unique evolutionary characteristics. Based on the most recent exploration progress in this region, the structural characteristics and active parameters of the buried hill faults in this region were quantitatively analyzed using the balanced section technique. In addition, the structural evolution process of the study area was reproduced by combining the structural-physical simulation experiment. Its spatio-temporal evolution characteristics and genesis mechanisms were also systematically investigated. As observed, the study area developed three basic sets of fault systems: the NW-trending extensional strike-slip fault, the NNE-trending left-handed compression–torsion fault, and the near-EW-trending extensional fault. The study area was further segmented into six buried hills: West Row Hill, Middle Row Hill, East Row Hill, Zhuanghai Buried Hill, Zhuangxi Buried Hill, and Changdi Buried Hill. The inner fault of the NW-trending Buried Hill is a strike-slip extensional fault that formed under the influence of the right-lateral strike-slip activity of the NW-trending Chengbei Fault from the Late Jurassic to the Early Cretaceous. In particular, the NNE-trending fault was a left-handed compression–torsion fault that formed under the left-handed strike-slip activity and regional compression stress field of the Tanlu fault zone. The near-EW fault was closely related to the near-SN extension stress field in the Late Cretaceous. Since the late Triassic, the study area has experienced six evolution stages, namely, overall uplift erosion (T3), overall coating deposition (J1+2), fault segmentation (J3-K1), extrusion uplift differentiation (K2), middle buried hill differentiation E), and overall stable subsidence (N-Q). Its tectonic evolution was primarily controlled by the significant variations in the tectonic stress field in the study area as well as its adjacent areas since the late Triassic, which were controlled by the tectonic stress field.

Study into torsion compression of hybrid blank made of Al—3Ca—Mn—Zn—Fe—Si alloy

Experimental studies of two blanks made of the same Al—3Ca—Mn—Zn—Fe—Si aluminum alloy are performed. The technology for obtaining a composite (hybrid) blank is associated with a torsion compression scheme and consists in the joint deformation of components from materials assembled into a composite blank, as a result of which they seize under the action of pressure, temperature, and also an increasing deformation in the frictional area of the rotating tool. In this case, the temperature in the joint zone does not reach the values typical for the stir welding process. The results of full-scale experiments and computer simulation modeling performed using the found rheological model of the Al—3Ca—Mn—Zn—Fe—Si alloy are presented. Examples of manufacturing of hybrid blank made of various alloys are given for a comparative comparison of the joint quality.

Influence of strain rate on grain refinement and texture evolution under complex shear stress conditions

The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated. With increasing strain rate, the average grain size of compression-shear (CS) and compression-torsion (CT) samples are decreased, and the grain size of dynamic recrystallization (DRX) grains is also decreased. This is because that the precipitation number of β phases is increased, and the hindering effect on grain growth can be significantly enhanced. The DRX fractions of CS and CT samples are decreased with increased strain rate. The low DRX fraction at high strain rate is related to the insufficient time for grains to nucleate. The DRX process can be promoted by the PSN mechanism of second phases, and the grain growth can be restricted by the pinning effect. At the same time, the texture strength is enhanced as the strain rate increased. Besides, the kinking degree of lamellar long-period stacking ordered (LPSO) phases is increased. Under complex shear stress conditions, non-basal slip, especially pyramidal slip, is easily activated and the texture is deflected greatly. Compared with the CS samples, CT samples have smaller average grain size, higher DRX fraction, and lower texture strength for a certain strain rate. This is because that the equivalent stress of the CT sample is larger, the stress triaxiality is smaller, so more serious dislocations are piled up near grain boundaries and second phases. At the same time, since CT sample was sheared with torsion, the dislocation movement path can be called “rotational dislocation accumulation”, and the longer distribution path of the CT sample is generated, so more sub-grains and low-angle grain boundaries (LAGBs) are formed. Compared with the CS sample, more huge-angle grain boundaries (HAGBs) and DRX grains are formed from grain boundary to grain interior, so better grain refinement effect is achieved.

Combining 3D Geological Modeling and 3D Spectral Modeling for Deep Mineral Exploration in the Zhaoxian Gold Deposit, Shandong Province, China

The Jiaodong Peninsula hosts the main large gold deposits and was the first gold production area in China; multisource and multiscale geoscience datasets are available. The area is the biggest drilling mineral-exploration zone in China. This study used three-dimensional (3D) modeling, geology, and ore body and alteration datasets to extract and synthesize mineralization information and analyze the exploration targeting in the Zhaoxian gold deposit in the northwestern Jiaodong Peninsula. The methodology and results are summarized as follows: The regional Jiaojia fault is the key exploration criterion of the gold deposit. The compression torsion characteristics and concave–convex section zones in the 3D deep environment are the main indicators of mineral exploration using 3D geological and ore-body modeling in the Zhaoxian gold deposit. The hyperspectral detailed measurement, interpretation, and data mining used drill-hole data (>1000 m) to analyze the vectors and trends of the ore body and ore-forming fault and the alteration-zone rocks in the Zhaoxian gold deposit. The short-wave infrared Pos2200 values and illite crystallinity in the alteration zone can be used to identify 3D deep gold mineralization and potential targets for mineral exploration. This research methodology can be globally used for other deep mineral explorations.

An Experimental Investigation of the Influence of the State of Stress on the Ductile Fracture of 2024-T351 Aluminum

Abstract This paper investigates the influence of stress state on the equivalent plastic fracture strain in 2024-T351 aluminum alloy. Eighteen unique stress states at failure—with triaxialities ranging from 0.388 (compressive) to −0.891 (tensile) and Lode parameters ranging from −0.978 to 1.000—are explored through mechanical experiments on 2024-T351 aluminum specimens with various geometries under multiple loading conditions. These include tension tests of plane stress (thin), plane strain (thick), and axisymmetric specimens, as well as pure shear and combined axial–torsional loading on thin-walled tubes. Using a hybrid numerical–experimental approach, the dependence of fracture strain on stress triaxiality and Lode parameter is quantified for each experiment. Fracture strains are measured using three-dimensional digital image correlation. Equivalent plastic fracture strain for 2024-T351 generally increases with stress triaxiality (moving toward a more compressive state). Fracture strain decreases modestly as the Lode parameter decreases from 1 to 0, although there is a significant increase in ductility as the Lode parameter decreases below −0.8. Compression–torsion tests extend the data’s stress-space coverage well into the compressive triaxiality region (up to 0.388) and to Lode parameters approaching −1. This experimental program provides the most extensive set of ductile fracture data from a single 12.7-mm-thick 2024-T351 aluminum plate in the literature. These data can be used to calibrate ductile fracture models used in finite element simulations of dynamic events such as bird strikes, automotive collisions, and debris containment.

Yield surface derivation for a structural adhesive based on multiaxial experiments

Yield surface determination is an essential part of a material characterization, enabling the qualification of a suitable yield criterion. In the case of two-component, fiber-reinforced structural adhesives the manufacturing quality of the specimens is directly linked to the determination accuracy of the yield surface. Therefore, this work was based on specimens that have been optimized in a previous study utilizing a structural, epoxy-based adhesive designed for the manufacture of wind turbine rotor blades. This allowed for a precise identification of a yield locus in combined tension–torsion and compression–torsion experiments. A practical elasto-plastic shear stress correction was developed to account for the transition between elastic and plastic states. In addition, a scaling method of an elliptical yield locus fitting function is proposed to calculate equivalent stresses and strains. The obtained results are discussed regarding influences of viscoelasticity and are compared to existing yield criteria.

Experimental study on Tapered Concrete-Filled Double Skin Steel Tubular columns under torsion

Recent developments in the high-output wind turbine have heightened the need for CFDST support towers. Tapered Concrete-Filled Double Skin Steel Tubular columns with Large Hollow Ratios (TLHR-CFDSTs) are the typical members in the wind turbine towers, which are usually subjected to torsion during the life cycle. It is necessary to pay more attention to these members under torsion due to their tapered shapes and thin-walled cross sections. This paper thus presents an experimental study on the torsional behaviour of the TLHR-CFDST column. Specimens with different tapered angles, hollow ratios, tubes’ thicknesses and axial compression ratios were tested under pure torsion and compression–torsion. The typical failure modes, torque versus deformation relations, strain distributions and the influence of important parameters are revealed. Based on the experimental results, the mechanism of TLHR-CFDST columns under torsion is discussed. The applicability of existing torsional capacity calculation methods is evaluated and finally a simplified method for predicting the torsional capacity of TLHR-CFDST columns is proposed.

Analytical study on the composite behavior of rectangular CFST columns under combined compression and torsion

In this paper, a total of 44 rectangular CFST column finite element models are established and verified. The effect of loading path, the working mechanism and the constraint interaction of rectangular CFST column under compression-torsion loading are discussed. The obtained results show that the ultimate axial bearing capacity of CFST column is decreased when the torsional moment is applied first, and the ultimate torsional capacity is increased when the compression force is applied first. The working mechanism of the compression-torsion CFST column can be simplified as unity of “pulling/compressive torsion” of the steel tube and “compressive torsion” of the core concrete. Finally, the torque-axial force correlative formula of rectangular CFST column is proposed, and is verified well with the test results and finite element results with higher accuracy and less dispersion.

Biomechanical properties of a novel fixation system for intra-articular distal humerus fractures: a finite element analysis

BackgroundThe traditional strategy for fixing intra-articular distal humerus fractures is double plating placed in an orthogonal configuration, based on posterior approach. With a combined medial and lateral approach, a novel configuration of plating (combined anteromedial and anterolateral plating) has been used. In this study, we investigated the biomechanical properties of the novel plating by comparing it with some traditional strategies.MethodsBased on the 3D morphology of a healthy subject’s humerus, models of three types of intra-articular distal humeral fractures were established using a variety of different internal fixation methods: (a) treatment of a simple intra-articular fracture of the distal humerus with the novel double plate and a traditional orthogonal plate; (b) treatment of a comminuted fracture of the lower distal humerus with the novel double plate, a traditional orthogonal plate and a traditional orthogonal plate combined with distally extended tension screws; (c) treatment of a coronal shear fracture of the distal humerus with the novel double plate, a traditional orthogonal plate and the intra-articular placement of three screws. The material properties of all plates and screws were isotropic and linearly elastic. The Poisson ratio of the implant and bone was 0.3, and the elastic modulus of the implant was 114,000 MPa. The axial loading is 200 N, the bending loading is 30 N and varus rotation is 7.5 Nm in the longitudinal direction.ResultsA simple model of intra-articular fracture of the distal humerus (AO C1 type) was established. Under all experimental conditions, the novel double plate showed greater stiffness than the orthogonal double plate. The axial straightening, bending compression and varus torsion increased by 18.00%, 16.00% and 44.00%, respectively. In the model of comminuted fracture of the lower distal humerus, the novel double plate showed the best stiffness under three experimental conditions (163.93 N/mm, 37.97 N/mm, 2697.84 N mm/°), and the stiffness of the traditional orthogonal plate combined with the distally extended tension screws was similar to that of the traditional orthogonal plate (121.21 N/mm, 32.61 N/mm, 1968.50 N mm/°). In the model of coronal shear fracture of the distal humerus, the novel double plate showed the best stiffness under all test conditions (194.17 N/mm, 38.46 N/mm, 2929.69 N mm/°), followed by the traditional plate (153.85 N/mm, 33.33 N/mm, 2650.18 N mm/°), while the stiffness of the three screws was the smallest (115.61 N/mm, 28.30 N/mm, 2180.23 N mm/°).ConclusionsIn terms of biomechanics, compared with other internal fixation methods, the novel combined anteromedial and anterolateral anatomical locking double-plate showed less stress, less displacement and greater stiffness. The novel double-plate method can be used to treat not only simple intra-articular fractures of the humerus but also complex comminuted fractures of the lower distal humerus and coronal shear fractures of the distal humerus, with a better effect than current traditional internal fixation methods.

Torsional bandgap switching in metamaterials with compression–torsion interacted origami resonators

Torsional vibrations are unavoidable in beam-type structures in various engineering practices, and the advent of metamaterials provides a solution through the generation of bandgaps. However, unlike their flexural counterparts, tunable torsional bandgaps are seldomly studied due to two major difficulties: the existing metamaterial's units are less torsional-sensitive and the reliable torsional sensing techniques for validations are less available. In this work, switchable torsional bandgaps are realized in a metamaterial beam with a bistable resonator design based on Kresling origami with attached eccentric balls. We find that, through compression–torsion interaction of the proposed origami resonators and the corresponding wave-coupling phenomenon, torsional bandgaps can be generated and efficiently tuned, which leads to lower and wider vibration isolation frequency zones. Thanks to bistability, Kresling resonators arranged with eccentric balls can achieve bandgap switching. Specifically, based on the compression–torsion interaction of the bistable Kresling origami, wave coupling will be weakened/enhanced when the Kresling resonators arranged with eccentric balls turn from the 1st/2nd state to the 2nd/1st state, and, thus, the switching of torsional bandgaps can be realized. In order to experimentally validate the tunable torsional bandgaps, a high-sensitive fiber Bragg grating (FBG) displacement sensing system containing two parallel FBG sensors is set up to extract the torsional responses. This research will be helpful for future studies focusing on regulating torsional waves through compression–torsion interaction and mode conversion utilizing wave coupling.

DEM investigation on the mechanical behavior of mudstone in the hollow cylinder torsional shear test

The discrete element method (DEM) has been used to investigate the mechanical and failure behavior and the associated micro-cracking process of mudstone under the hollow cylinder torsional test by using a commercial DEM code PFC3D. Micro-parameters of the numerical model were first calibrated to the experimental results of the uniaxial compression tests and the uniaxial tensile tests. Based on the calibration results, numerical hollow cylindrical torsional shear tests were carried out under three typical stress conditions, i.e. triaxial compression, torsional compression and pure torsional shear. The numerical results show that the mechanical behavior of mudstone, in terms of rock strength, micro-crack initiation and propagation, and failure mode, can be significantly affected by principal stress rotation, which is in line with previous experimental results. The analysis of the micro-crack process confirms that the principal stress rotation plays an important role in the initiation and propagation of micro-cracks. It is shown that the microcracks induced by tensile stress occur in a preferential direction parallel to the major principal stress σ1, while the orientation distribution of the shear micro-cracks is related to the shear bands. Furthermore, the initial micro-crack stress is found to decrease after introducing the principal stress rotation, which provides a new interpretation of degradation of strength and permeability of mudstone under principal stress rotation. Three typical failure modes of specimens in different loading states are reproduced in this study, and the microscopic mechanism is also discussed. Based on this study, it is found that ignoring the principal stress rotation may overrate the stability and tightness of underground storage in bedded rock salt caverns.

A novel chiral metamaterial with multistability and programmable stiffness

Chiral metamaterials are widely studied for their unique mechanical properties, but still have problems such as low stiffness and few available scenarios. Based on the tetra-chiral metamaterial, a type of metamaterial with programmable stiffness and multistability is designed in this paper. The stiffness of two-dimensional (2D) metamaterial can be adjusted programmatically by changing its geometric parameters. The equivalent elastic modulus and Poisson’s ratio were obtained by using an analytical solution and finite element method. Then the 2D metamaterials were extended to cylindrical tubes with multistability. The deformation patterns of the 2D metamaterials and cylindrical tubes with different geometric parameters were investigated. It is found that the cylindrical tubes can exhibit compression–torsion coupling and multistability deformation characteristics. This work can provide a valuable reference for designs of novel metamaterials with coupled deformation, as well as further expanding the field of application.

Fabrication of Metal Matrix Composite Containing Manganese Nitride Showing Giant Negative Thermal Expansion by Compressive Torsion Processing

Fabrication of Metal Matrix Composite Containing Manganese Nitride Showing Giant Negative Thermal Expansion by Compressive Torsion Processing