Showing papers on "Deformation (meteorology) published in 2022"
TL;DR: In this paper , a review article summarizes the hot deformation behavior of high entropy alloys (HEAs) and the corresponding constitutive description of flow stress for grain refinement via dynamic recrystallization (DRX), reduction of casting defects, and enhancement of mechanical properties of HEAs.
93 citations
01 Jan 2022
TL;DR: Wang et al. as discussed by the authors proposed a soft tissue grasping deformation model, where BP neural network optimized by the genetic algorithm was used to realize the real-time and accurate interaction of soft tissue grasps during virtual surgery.
Abstract: This paper proposes a soft tissue grasping deformation model, where BP neural network optimized by the genetic algorithm is used to realize the real-time and accurate interaction of soft tissue grasping during virtual surgery. In the model, the soft tissue epidermis is divided into meshes, and the meshes generate displacements under the action of tension. The relationship between the tension and displacement of the mesh is determined by the proposed cylindrical spiral spring model. The optimized BP neural network is trained based on the sample data of the mesh point and vertical tension, so as to obtain the force and displacement of any mesh point on the soft tissue epidermis. The virtual experiment platform is built using a PHANTOM OMNI haptic hand controller and the 3D Max software, by which the simulation experiment of grasping the human abdomen is realized. The experimental results show that the proposed model has good visual interaction and real-time force feedback, which can meet the requirements of deformation simulation for soft tissue grasping in virtual surgery.
80 citations
80 citations
TL;DR: Lihua et al. as mentioned in this paper conducted an in situ atomic-resolution study to reveal how sliding-dominant deformation is accomplished at general tilt GBs in platinum bicrystals.
Abstract: Grain boundaries (GBs) play an important role in the mechanical behavior of polycrystalline materials. Despite decades of investigation, the atomic-scale dynamic processes of GB deformation remain elusive, particularly for the GBs in polycrystals, which are commonly of the asymmetric and general type. We conducted an in situ atomic-resolution study to reveal how sliding-dominant deformation is accomplished at general tilt GBs in platinum bicrystals. We observed either direct atomic-scale sliding along the GB or sliding with atom transfer across the boundary plane. The latter sliding process was mediated by movements of disconnections that enabled the transport of GB atoms, leading to a previously unrecognized mode of coupled GB sliding and atomic plane transfer. These results enable an atomic-scale understanding of how general GBs slide in polycrystalline materials. Description Pushing the grain boundaries The behavior of grain boundaries in metals during deformation is important because it can dictate the macroscopic behavior. Lihua et al. used aberration-corrected in situ electron microscopy observation of platinum grain boundaries during straining to detail how they evolve. The authors observed grain boundary sliding, which is a well-known and expected mechanism. However, the authors also observed a unexpected mechanism that involves the removal of lattice planes at the grain boundaries. Their observations show the importance of using very-high-resolution microscopy to understand the role of grain boundaries during deformation. —BG Electron microscopy shows that platinum grain boundaries evolve in unexpected ways during straining.
76 citations
TL;DR: Wang et al. as discussed by the authors used three-dimensional dynamic scanning technology to reconstruct the fracture morphology of disced cores extracted from Songke-2 as well as part of the Chinese Continental Scientific Drilling Project.
74 citations
TL;DR: In this article , a method to further enhance the mechanical properties of auxetic composites has been proposed, which is implemented by designing joints of frames, and the results of finite element analysis and experiments exhibit a good agreement.
61 citations
TL;DR: In this paper , low cycle reciprocating load tests were conducted on nine recycled aggregate concrete-filled steel tube columns (RACSTCs) and a solitary ordinary concrete filled steel tube contrast column (OCSTC), and the axial compression ratio and steel-tube wall thickness were considered as the parameters of interest.
60 citations
TL;DR: In this paper , a deformation-driven metallurgy-based aluminum matrix composites with a uniform dispersion of graphene nanoplatelets and ultra-fine microstructures were obtained via severe plastic deformation and dynamic recrystallization.
Abstract: 1.5 wt% graphene nanoplatelet-reinforced aluminum matrix composites were prepared by deformation-driven metallurgy to ameliorate strength-ductility efficiency. Severe plastic deformation with its frictional/deformation heat introduced by deformation-driven metallurgy was studied by their strengthening-toughing behaviors related to graphene nanoplatelet dispersion, interfacial bonding, and grain refinement. The synergy strengthening behaviors were studied via modeling analysis. Uniform dispersion of graphene nanoplatelets and ultra-fine microstructures (267.0 nm) were obtained via severe plastic deformation and dynamic recrystallization. High-efficiency interfacial bonding was realized via graphene nanoplatelets-(amorphous Al 2 O 3 )-Al semi-direct interface without the formation of Al 4 C 3 . The automatic flow of Al 2 O 3 nanodots to compensate for the spatial discontinuity caused by the interlayer slip of graphene was observed to achieve self-compensating spatial continuity. The ultimate tensile strength and elongation reached 468 ± 7 MPa and 19.9 ± 0.6%, respectively, showing an enhancement of strength by 293.3% with almost no loss in ductility.
56 citations
TL;DR: In this paper , the structure, elastic properties and ductility of TM5SiC2(TM = Cr, Mo, Nb and W) ternary silicides are studied by the first-principles calculations.
54 citations
TL;DR: In this article , the impact dynamics experiments were conducted to study energy characteristics based on split Hopkinson pressure bar (SHPB) system, and the incident, reflected and transmission strain were collected to calculate various energy.
54 citations
TL;DR: In this paper , a multistage constant-amplitude-cyclic (MCAC) loading experiments were conducted on interbedded skarns to investigate and characterize fatigue mechanical behavior of the tested rock.
TL;DR: Wang et al. as discussed by the authors simulated the deformation process of a large and steep rock slope in Dexing City, Jiangxi Province, China, under a variable rainfall event and showed that the increased deformation region has positive relationships with increasing pore water pressure and water content values for the open-pit mine rock slope affected by heavy rainfall.
TL;DR: In this article, the in-plane energy absorption characteristics of modified re-entrant auxetic honeycombs realized via fused filament fabrication in conjunction with parametric analysis and geometry optimization were evaluated.
Abstract: Here, we present the in-plane energy absorption characteristics of modified re-entrant auxetic honeycombs realized via fused filament fabrication in conjunction with parametric analysis and geometry optimization. The influence and interaction effects of the geometrical parameters such as strut-length ratio and joint-angles on the stiffness, strength and energy absorption characteristics of modified re-entrant auxetic honeycombs were evaluated. Subsequently, Finite Element results obtained using ABAQUS/Explicit were corroborated with measured data. Deformation mode, stress-strain response and energy absorption behavior of an optimal re-entrant auxetic honeycomb were studied and compared with conventional re-entrant auxetic structure. Modified auxetic structure reveals an 36% improvement in the specific energy absorption capacity. Our analysis further indicates that due to the introduction of more nodes with low rotational stiffness, the failure strain of the modified re-entrant structure has increased resulting in improved energy absorption capacity.
TL;DR: In this article , the in-plane energy absorption characteristics of modified re-entrant auxetic honeycombs realized via fused filament fabrication in conjunction with parametric analysis and geometry optimization were evaluated.
Abstract: Here, we present the in-plane energy absorption characteristics of modified re-entrant auxetic honeycombs realized via fused filament fabrication in conjunction with parametric analysis and geometry optimization. The influence and interaction effects of the geometrical parameters such as strut-length ratio and joint-angles on the stiffness, strength and energy absorption characteristics of modified re-entrant auxetic honeycombs were evaluated. Subsequently, Finite Element results obtained using ABAQUS/Explicit were corroborated with measured data. Deformation mode, stress-strain response and energy absorption behavior of an optimal re-entrant auxetic honeycomb were studied and compared with conventional re-entrant auxetic structure. Modified auxetic structure reveals an 36% improvement in the specific energy absorption capacity. Our analysis further indicates that due to the introduction of more nodes with low rotational stiffness, the failure strain of the modified re-entrant structure has increased resulting in improved energy absorption capacity.
TL;DR: In this paper, the authors reviewed the research progress of deformation processing and heat treatment of Mg-Li alloys, with particular emphasis on the factors affecting the plastic deformation, the effects of plastic deformations on microstructural evolution and mechanical properties.
TL;DR: In this article , the research progress of deformation processing and heat treatment of Mg-Li alloys is reviewed, with particular emphasis on the factors affecting the plastic deformation.
TL;DR: In this paper , a low expansion electrode particle is investigated for mechanical stresses during lithiation with intrinsic and extrinsic factors including local deformation, concentration dependent properties, and external constraints.
Abstract: In this article, a low expansion electrode particle is investigated for mechanical stresses during lithiation with intrinsic and extrinsic factors included. The stress states are estimated with local deformation, concentration dependent properties, and external constraints. It is observed that lithiation of an unconstrained electrode particle lead to reduced concentration gradient of Li-ions with increase in stress magnitude for a case where the particle show concentration dependent stiffening response. Whereas, the constrained expansion of the same electrode particle result in reduced and elevated concentration gradient at near-field and far-field locations, respectively. Influence of charging rate is also reported wherein limiting stress (threshold limit) is observed with increasing charging rate. Further, at elevated charging rates, a drastic reduction in concentration gradient is observed at the surface of the electrode particle. • Li-Ion concentration dependent stiffening of low-expansion electrode particle is modeled. • Correlation between charging rate and concentration dependent modulus is explored. • The stresses developed in the particle is observed to vary differentially with charging rate. • Lithiation induced stresses are observed to increase for constrained particle. • Inhomogeneous concentration gradient is quantified in constrained particle.
01 Jan 2022-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, an NAB/15-5-PH interface without cracks and lack of fusion was achieved, which was characterized with an interlayer of FexAl dendrites.
Abstract: Additive manufacturing (AM) of a nickel-aluminum-bronze (NAB)/15-5 PH multimaterial by laser-powder directed energy deposition (LP-DED) accomplished a combination of excellent mechanical performance and high corrosion resistance. An NAB/15-5 PH interface without cracks and lack of fusion was achieved, which was characterized with an interlayer of FexAl dendrites. The formation of the interfacial characteristics was attributed to a synthetic effect of liquid phase separation, Marangoni convection, and atom diffusion. A miscibility gap was generated by a high degree of supercooling in the melt pool, and 15-5 PH solidified prior to NAB to form a dendritic interlayer. Marangoni convection occurred to promote the Al atom diffusion from NAB to 15-5 PH, contributing to the formation of the FexAl phase at the interface. The multimaterial sample possessed higher ultimate tensile strength of 754.64 MPa in the transverse direction and 854.57 MPa in the longitudinal direction as compared to that of copper/steel counterparts fabricated by AM. The multimaterial printed by LP-DED exhibited different deformation mechanisms in the transverse and longitudinal directions. In the transverse direction, NAB contributed more deformation than 15-5 PH and determined the improved ductility of the multimaterial; in the longitudinal direction, the brittle FexAl dendrites constrained the deformation of NAB and 15-5 PH, which resulted in the early failure of the multimaterial. The multimaterial tended to undergo cracking at the interface of the FexAl and Cu phases under stress concentration, which was induced by their crystal incoherence.
TL;DR: In this article , the deformation mechanism of Mg alloy sheets was investigated by pre-strain paths, i.e., tension (6%) and compression (5%) perpendicular to the c-axis along extrusion direction.
TL;DR: A detailed analytical computation of support characteristic curve (SCC) for circumferential yielding lining, which is a significant aspect of the implementation of convergence-confinement method (CCM) in tunnel support design, is presented in this article .
Abstract: Circumferential yielding lining is able to tolerate controlled displacements without failure, which has been proven to be an effective solution to large deformation problem in squeezing tunnels. However, up to now, there has not been a well-established design method for it. This paper aims to present a detailed analytical computation of support characteristic curve (SCC) for circumferential yielding lining, which is a significant aspect of the implementation of convergence-confinement method (CCM) in tunnel support design. Circumferential yielding lining consists of segmental shotcrete linings and highly deformable elements, and its superior performance mainly depends on the mechanical characteristic of highly deformable element. The deformation behavior of highly deformable element is firstly investigated. Its whole deforming process can be divided into three stages including elastic, yielding and compaction stages. Especially in the compaction stage of highly deformable element, a nonlinear stress–strain relationship can be observed. For mathematical convenience, the stress–strain curve in this period is processed as several linear sub-curves. Then, the reasons for closure of circumferential yielding lining in different stages are explained, and the corresponding accurate equations required for constructing the SCC are provided. Furthermore, this paper carries out two case studies illustrating the application of all equations needed to construct the SCC for circumferential yielding lining, where the reliability and feasibility of theoretical derivation are also well verified. Finally, this paper discusses the sensitivity of sub-division in element compaction stage and the influence of element length on SCC. The outcome of this paper could be used in the design of proper circumferential yielding lining.
01 Jan 2022-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper , an NAB/15-5 PH interface without cracks and lack of fusion was achieved, which was characterized with an interlayer of FexAl dendrites.
Abstract: Additive manufacturing (AM) of a nickel-aluminum-bronze (NAB)/15-5 PH multimaterial by laser-powder directed energy deposition (LP-DED) accomplished a combination of excellent mechanical performance and high corrosion resistance. An NAB/15-5 PH interface without cracks and lack of fusion was achieved, which was characterized with an interlayer of FexAl dendrites. The formation of the interfacial characteristics was attributed to a synthetic effect of liquid phase separation, Marangoni convection, and atom diffusion. A miscibility gap was generated by a high degree of supercooling in the melt pool, and 15-5 PH solidified prior to NAB to form a dendritic interlayer. Marangoni convection occurred to promote the Al atom diffusion from NAB to 15-5 PH, contributing to the formation of the FexAl phase at the interface. The multimaterial sample possessed higher ultimate tensile strength of 754.64 MPa in the transverse direction and 854.57 MPa in the longitudinal direction as compared to that of copper/steel counterparts fabricated by AM. The multimaterial printed by LP-DED exhibited different deformation mechanisms in the transverse and longitudinal directions. In the transverse direction, NAB contributed more deformation than 15-5 PH and determined the improved ductility of the multimaterial; in the longitudinal direction, the brittle FexAl dendrites constrained the deformation of NAB and 15-5 PH, which resulted in the early failure of the multimaterial. The multimaterial tended to undergo cracking at the interface of the FexAl and Cu phases under stress concentration, which was induced by their crystal incoherence.
TL;DR: In this article , microstructure and texture evolution during plastic deformation and annealing treatment of near beta (β), meta-stable β, and stable β-Ti alloys are reviewed.
TL;DR: In this paper , the authors analyzed the roof movement and deformation of an ultra-large height mining face, and the working resistance of the ultra large height mine face was obtained by introducing the equivalent immediate roof.
Abstract: Surrounding rock control and support stability in the process of coal seam mining in ultra-large height mining face are the key to normal mine operation. In this study, the roof movement and deformation of an ultra-large height mining face are analyzed, and the working resistance of the ultra-large height mining face is obtained by introducing the equivalent immediate roof. By analyzing the coal wall spalling, the multiple positions of the spalling and the required support force of the support are obtained. At the same time, ultra-large height supports are more prone to instability problems. In this study, the stability of the ultra-large height supports was analyzed by establishing a mechanical model. The results show that: 1. The overturning limit angle of support has a hyperbolic relationship with the center of gravity. 2. Under the condition of ultra-large height, the increase in the base width of the bracket significantly improves the stability of the supports. 3. The sliding limit angle of support is positively correlated with the support load and the friction coefficient between the support and the floor. The above conclusions can provide guidance on the selection of supports and the adoption of measures to enhance the stability of the supports during use under ultra-large height conditions. The working resistance of the ultra-large height supports in the 108 mining face of the Jinjitan Coal Mine was monitored. The monitoring results show that: The average resistance of the supports is 22.6 MPa. The selected supports can meet the stability requirements of the working face support. The frequency of mining resistance in 0~5 MPa accounts for 28.38%, which indicates that some supports are insufficient for the initial support force during the moving process. Furthermore, the stability of the supports can be enhanced by adjusting the moving process. This study provides a reference for the selection of supports in ultra-large height mining faces and proposes measures to enhance the stability of the supports, which provides guidance for the safe mining of coal in ultra-large height mining faces.
TL;DR: In this article , the first-principles calculations are adopted to perform the insight to Bi-Ge-O ternary compounds, such as Cmc21-type-Bi2GeO5, Bi4Ge3O12, C1c1-type -Bi2GEO5 and Bi12GeO20.
TL;DR: This study applies an advanced deep machine learning method called gated recurrent unit (GRU) to the displacement prediction of the Jiuxianping landslide, which is a typical reservoir landslide located in the Yunyang County of Chongqing, China.
TL;DR: In this article, a permafrost-tailored InSAR approach was developed by incorporating a MODIS-land-surface-temperature-integrated ground deformation model to reconstruct the seasonal and long-term deformation.
TL;DR: Wang et al. as discussed by the authors developed a digital acquisition technique to quickly, automatically, and accurately obtain the in-situ strength parameters (e.g., GSI and D), followed by the establishment of a threedimensional (3D) numerical model for deep tunneling for a typical tunnel in western China to study the 3D and nonlinear spatial effects and mechanisms during excavation with incorporation of 3D Hoek-Brown (HB) strength criterion.
TL;DR: In this article , a permafrost-tailored InSAR approach was developed by incorporating a MODIS-land-surface-temperature-integrated ground deformation model to reconstruct the seasonal and long-term deformation.
01 Mar 2022
TL;DR: In this paper , a novel energy absorber by mimicking the structural characteristics of animal long bone, namely bio-inspired multi-cell tube (BIMCT), which comprises laterally-graded multicell configuration and the axially-graded aluminum foam was respectively fabricated with steel and aluminum for quasi-static crushing tests.
Abstract: Bio-inspired thin-walled structures have gained growing interests attributed to their excellent performance of energy absorption and lightweight. This study proposes a novel energy absorber by mimicking the structural characteristics of animal long bone, namely bio-inspired multi-cell tube (BIMCT), which comprises laterally-graded multi-cell configuration and the axially-graded aluminum foam. The BIMCTs were respectively fabricated with steel and aluminum for quasi-static crushing tests to explore the corresponding deformation mechanisms, force-displacement curves and interactive effects between tube wall and foam filler. The experimental tests indicated that the steel BIMCT generated a more stable and more regular deformation mode, presenting noticeably higher specific energy absorption (SEA). Furthermore, a numerical modeling study was conducted on the steel BIMCT to analyze the energy absorption mechanism, effects of thickness gradient kt, foam density gradient ktf and average density ρ‾avg of foam on the force-displacement curves, energy absorption (EA), peak crush force (PCF), SEA and the interactive effects between the tube wall and graded metallic foam. Finally, a theoretical model was developed based upon the so-called simplified super folding element method to predict the mean crushing force of BIMCT analytically. The comparative analysis results indicated that the proposed theoretical model is applicable of both the BIMCT and its empty counterpart. This study is anticipated to demonstrate a new way for developing a superior bio-inspired structure for energy absorption.
TL;DR: In this paper, the anisotropy dependence of material removal and deformation behaviors was investigated systematically, and the results showed that crack-free plastic deformation of GaN crystals could be acquired along different zone axes, which was dominated by phase transition, polycrystalline nanocrystals, amorphous transition, as well as close-to-atomic scale damages including stacking faults, dislocations and lattice distortions.