complex deformation
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Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 221
Author(s):  
Xiaoting Luo ◽  
Zhiheng Huang ◽  
Shuanjin Wang ◽  
Min Xiao ◽  
Yuezhong Meng ◽  
...  

As thermal management in 3DIC integration becomes increasingly important in advanced semiconductor node processes, novel experimental and modeling approaches are in great demand to reveal the critical material issues involving multiscale microstructures that govern the behavior of through-silicon-via (TSV) protrusion. Here, a coarse-grained phase-field crystal model properly coupled with mechanics through the atomic density field is used to simulate the formation of polycrystalline structures and protrusion of nano-TSVs from the atomic scale. TSVs with different grain structures are directly loaded, and protrusion/intrusion profiles are obtained along with displacement, stress, and strain fields. Thermodynamic driving forces from external loadings and the mismatch of Young’s modulus between adjoining grains as well as detailed displacement and strain distributions are ascribed to control the complex deformation in TSVs. TSVs with sizes up to around 30 nm and an aspect ratio of 4 are successfully investigated, and a further increase in the size and aspect ratio to cover the micrometer range is feasible, which lays down a solid basis toward a multiscale material database for simulation inputs to the design of TSV-based 3DIC integration and relevant electronic design automation (EDA) tools.


2022 ◽  
Author(s):  
ZHIBIN LEI ◽  
J. Davies

Dual inward dipping subduction often produces complex deformation patterns in the overriding plate. However, the geodynamic process of how dual inward dipping subduction relates to this deformation is still poorly understood. Here we apply a composite viscosity, dependent on multiple parameters, e.g., temperature, pressure, strain rate etc., in 2-D thermo-mechanical numerical modelling to investigate how dual inward dipping subduction modifies the rheological structure of the overriding plate. Three variables are investigated to understand what controls the maximum degree of weakening. We find that the initial length and thickness of the overriding plate are negatively correlated with the magnitude of viscosity reduction. While the initial thickness of the subducting plate positively relates to the magnitude of viscosity reduction. The progressive weakening can result in a variety of stretching states ranging from 1) little or no lithosphere thinning and extension, to 2) limited thermal lithosphere thinning, and 3) localised rifting followed by spreading extension. Compared with single sided subduction, dual inward dipping subduction further reduces the magnitude of viscosity of the overriding plate. It does this by creating a dynamic fixed boundary condition for the overriding plate and forming a stronger upwelling mantle flow underlying the overriding plate. Three types of feedback weakening cycles are recognised, among which the strain rate weakening mechanism plays the dominant role in lowering the viscosity of the overriding plate throughout the simulation. Strain rate weakening is also a precondition for initiating thermal weakening, strain localisation and lithosphere thinning.


Author(s):  
Shokoofeh Abbaszadeh ◽  
Roberto Leidhold ◽  
Stefan Hoerner

AbstractFish mortality assessments for turbine passages are currently performed by live-animal testing with up to a hundred thousand fish per year in Germany. A propelled sensor device could act as a fish surrogate. In this context, the study presented here investigates the state of the art via a thorough literature review on propulsion systems for aquatic robots. An evaluation of propulsion performance, weight, size and complexity of the motion achievable allows for the selection of an optimal concept for such a fish mimicking device carrying the sensors. In the second step, the design of a bioinspired soft robotic fish driven by an unconventional drive system is described. It is based on piezoceramic actuators, which allow for motion with five degrees of freedom (DOF) and the creation of complex bio-mimicking body motions. A kinematic model for the motion’s characteristics is developed, to achieve accurate position feedback with the use of strain gauges. Optical measurements validate the complex deformation of the body and deliver the basis for the calibration of the kinematic model. Finally, it can be shown, that the calibrated model presented allows the tracking of the deformation of the entire body with an accuracy of 0.1 mm.


2021 ◽  
Vol 11 (23) ◽  
pp. 11389
Author(s):  
Kuo-Lung Wang ◽  
Jun-Tin Lin ◽  
Hsun-Kuang Chu ◽  
Chao-Wei Chen ◽  
Chia-Hao Lu ◽  
...  

The area of Taiwan is 70% hillsides. In addition, the topography fluctuates wildly, and it is active in earthquakes and young orogenic movements. Landslides are a widespread disaster in Taiwan. However, landslides are not a disaster until someone enters the mountain area for development. Therefore, landslide displacement monitoring is the primary task of this study. Potential landslide areas with mostly slate geological conditions were selected as candidate sites in this study. The slate bedding in this area is approximately 30 to 75 degrees toward the southeast, which means that creep may occur due to gravity deformation caused by high-angle rock formation strikes. In addition, because the research site is located in a densely vegetated area, the data noise is very high, and it is not easy to obtain good results. This study chose ESA Sentinel-1 data for analysis and 1-m LiDAR DEM as reference elevation. The 1-m LiDAR DEM with high accuracy can help to detect more complex deformation from DInSAR. The Sentinel-1 series of satellites have a regular revisit period. In addition, the farm areas of roads, bridges, and buildings in the study area provided enough reflections to produce good coherence. Sentinel-1 images from March 2017 to June 2021 were analyzed, obtaining slope deformation and converting it to the vertical direction. Deformation derived from SAR is compared with other measurements, including GNSS and underground slope inclinometer. The SBAS solution process provides more DInSAR pairs to overcome the problem of tremendous noise and has increased accuracy. Moreover, the SBAS method’s parameter modification derives more candidate points in the vegetated area. The vertical deformation comparison between the GNSS installation location and the ascending SBAS solution’s vertical deformation is consistent. Moreover, the reliable facing of the slope toward the SAR satellite is discussed. Due to the limitations of the GNSS stations, this study proposes a method to convert the observed deformation from the slope inclinometer and convert it to vertical deformation. The displacement of the slope indicator is originally a horizontal displacement. It is assumed that it is fixed at the farthest underground, and the bottom-to-top movement is integrated with depth. The results show that the proposed equation to convert horizontal to vertical displacement fits well in this condition. The activity of landslides within the LiDAR digital elevation model identified as scars is also mapped.


2021 ◽  
Vol 2131 (3) ◽  
pp. 032017
Author(s):  
A Samoshkin ◽  
V Tikhomirov

Abstract The article developed a mathematical model describing the deformation of reinforced concrete, taking into account its adhesion to reinforcement. The model consists of three layers: concrete, contact layer, reinforcement. The contact layer surrounding the reinforcement takes into account the complex deformation of the concrete when interacting with the profiled reinforcement. Arguments are presented for criteria that determine the transition of concrete, reinforcement and contact layer to limit states. A diagram of testing of reinforced concrete specimen has been proposed and a procedure for processing experimental data, which allow you to determine the bond parameters. Equations that bind the mechanical characteristics of the contact layer with two the bond parameters of concrete with reinforcement are obtained. The developed model was used in the numerical solution of the problem of static pull-out of reinforcement from concrete. The calculation of the finite element method showed a good correspondence with the experimental data, including during plastic deformation of the reinforcement. This shows the correctness of theoretical provisions and developed mathematical algorithms used to model the deformation of reinforced concrete.


2021 ◽  
Vol 22 (4) ◽  
pp. 619-642
Author(s):  
O. E. Zasimchuk ◽  
M. G. Chausov ◽  
B. M. Mordyuk ◽  
O. I. Baskova ◽  
V. I. Zasimchuk ◽  
...  

Heterogeneous aluminium alloys are in demand in the aviation industry, where the ability of the material to withstand fatigue loads is important. The topic of the article is the search for the most experimentally available methods of deformation effect on such materials in order to increase fatigue life. Unfortunately, previous studies were ambiguous due to the large number of factors influencing the fatigue of metal materials under the same type of mechanical load; so, we chose a dynamic load with pulse loading. It turned out that for heterogeneous 2024-T351 and D16CzATW alloys, shock–vibration loading (SVL) applied during static straining prolongs their further fatigue life at a certain magnitude of the deformation during the action of the pulse. For example, for the 2024-T351 alloy at the maximum stress of alternating load σmax = 400 MPa, the longest fatigue life should be expected at deformations εimp = 2–4%; and at the maximum stress of alternating (fatigue) loading of 440 MPa, it is at εimp = 3–5%. In comparison with the average values of fatigue life of the D16CzAT alloy in the initial state, fatigue life after processing increases at σmax = 340 MPa alloy by 11.6%, at a stress of σmax = 370 MPa, by 18.4%, at a stress of σmax = 400 MPa, by 21.2%. The positive effect of long-term exposure after treatment on fatigue life was also noted. The influence of the strengthening phases, such as the nanosize Θ-Al2Cu and S-CuAl2Mg particles, on the separate stages of pre-treatment of alloys and the effects of their quantities on total fatigue durability is investigated by statistical methods of transmission electron microscopy. The great attention is paid to the mechanism of formation of fatigue fracture embryos in the near-surface areas of the samples, for which analytical calculations and the experimental method of ultrasonic impact treatment (UIT) are used. It is shown that the use of UIT after SVL does not affect the fatigue life of the 2024-T351 alloy at a fatigue load frequency of 15 Hz, while the single UIT increases fatigue life of the alloy. It is concluded that the use of complex deformation loads accelerates the relaxation processes, which shorten fatigue life.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhangbin Ji ◽  
Jian Zhou ◽  
Huamao Lin ◽  
Jianhui Wu ◽  
Dinghong Zhang ◽  
...  

AbstractFlexible surface acoustic wave (SAW) devices have recently attracted tremendous attention for their widespread application in sensing and microfluidics. However, for these applications, SAW devices often need to be bent into off-axis deformations between the acoustic wave propagation direction and bending direction. Currently, there are few studies on this topic, and the bending mechanisms during off-axis bending deformations have remained unexplored for multisensing applications. Herein, we fabricated aluminum nitride (AlN) flexible SAW devices by using high-quality AlN films deposited on flexible glass substrates and systematically investigated their complex deformation behaviors. A theoretical model was first developed using coupling wave equations and the boundary condition method to analyze the characteristics of the device with bending and off-axis deformation under elastic strains. The relationships between the frequency shifts of the SAW device and the bending strain and off-axis angle were obtained, and the results were identical to those from the theoretical calculations. Finally, we performed proof-of-concept demonstrations of its multisensing potential by monitoring human wrist movements at various off-axis angles and detecting UV light intensities on a curved surface, thus paving the way for the application of versatile flexible electronics.


2021 ◽  
Author(s):  
Peng Chen ◽  
Yi Yu ◽  
Yuwang Liu

Abstract The inherent compliance of continuum robots holds great promise in the fields of soft manipulation and safe human-robot interaction. This compliance reduces the risk of damage to the manipulated object and the surroundings. However, continuum robots have theoretically infinite degrees of freedom, and this high flexibility usually leads to complex deformations with external forces and positional constraints. How to describe this complex deformation is the main challenge for modelling continuum robots. In this study, we investigated a novel variable curvature modeling method for continuum robots, considering external forces and positional constraints. The robot configuration curve is described by the developed mechanics model, and then the robot is fitted to the curve. To validate the model, a 10-section continuum robot prototype with a length of 1 m was developed. The ability of the robot to reach the target points and track complex trajectories with load verified the feasibility and accuracy of the model. The ratio of the average position error of the robot endpoint to the robot length was less than 2.38%. This work may serve a new perspective for design analysis and motion control of continuum robots.


2021 ◽  
Author(s):  
Aileen L. Doran ◽  
Steven P. Hollis ◽  
Julian F. Menuge ◽  
Stephen J. Piercey ◽  
Adrian J. Boyce ◽  
...  

Abstract Irish-type Zn-Pb deposits are important global sources of zinc, but despite a fundamental understanding of ore genesis within the Irish orefield, a detailed understanding of fluid migration and chemical evolution pathways related to sulfide and carbonate precipitation is lacking. We present the first petrographic, paragenetically constrained sulfur isotope and mineral chemistry study of mineralization at the Island Pod orebody, Lisheen deposit. The Island Pod orebody comprises high-grade mineralization that is less deformed than elsewhere in the Irish orefield. Consequently, studies of the Island Pod orebody and its mineralization provide information on the evolving nature of hydrothermal fluids involved in ore deposition. The Island Pod orebody consists almost exclusively of pyrite, sphalerite, and galena, with several stages of calcite and dolomite precipitation. Pre-ore, diagenetic pyrite is commonly overgrown by early main ore-stage pyrite, with both phases frequently replaced by main ore-stage sphalerite. In many cases, early main ore-stage pyrite is texturally zoned and exhibits chemical zoning patterns, reflecting that episodic influxes of hydrothermal fluids contained variable concentrations of As, Co, Ni, and Tl. The main ore stage was dominated by the formation of sphalerite and galena from mineralizing fluids that were depleted in these trace elements (e.g., As, Co, Tl) compared to the early main ore stage. Sulfur isotope analysis reveals four distinctive but slightly overlapping isotopic groupings, corresponding to different mineral and paragenetic stages: (1) δ34S values range from –47.7 to –30.7‰, associated with diagenetic pyrite; (2) δ34S values range from –34.3 to –14.7‰, related to early main ore-stage pyrite; (3) δ34S values range from –15.5 to + 1.7‰, corresponding to main ore-stage sphalerite; and (4) δ34S values range from –11.1 to + 17.4‰, associated with galena. Large variations in S isotope composition are common at intragrain and at other small spatial scales. The textures, paragenetic sequence, and ranges in δ34S values are consistent with hydrothermal sulfide deposition where the fluids containing bacteriogenic sulfide mixed with metal-bearing fluids. Replacement and remobilization from other Lisheen orebodies may have contributed to some of the higher sulfur isotope ratios observed in the Island Pod orebody. The excellent preservation of sulfide textures in the Island Pod orebody observed during this study demonstrates that it is an ideal location to study hydrothermal fluid evolution, including episodic fluid flow, mixing, precipitation, and compositional variations during the early main ore stage. In other Irish Zn-Pb orebodies, these early-ore textures are often obscured due to more complex dissolution and replacement processes, making interpretation of the early hydrothermal activity challenging. Consequently, the petrographic, mineral chemistry, and sulfur isotope studies of the Island Pod orebody presented here contribute to an enhanced understanding of ore-forming processes in similar deposits, where mineralization is often associated with more complex deformation or repeated pulses of hydrothermal activity.


2021 ◽  
Vol 11 (19) ◽  
pp. 9235
Author(s):  
Hussein Zein ◽  
Osama M. Irfan

Deep drawing is characterized by extremely complex deformation that is influenced by process characteristics such as die and punch shapes, blank shape, blank holding force, material properties, and lubrication. The optimization of the deep drawing process is a challenging issue due to the complicated functions that define and relate the process parameters. However, the optimization is essential to enhance the productivity and the product cost in the deep drawing process. In this paper, a MATLAB toolbox (Pattern Search) was employed to minimize the maximum deep drawing force (Fd-min) at different values of the operating and the geometrical parameters. As a result, a minimum deep drawing force chart (carpet plot) was generated to show the best combination of friction coefficients at the blank contact interfaces. The extracted friction coefficients guided the selection of proper lubricants while minimizing the deep drawing force. A finite element analysis (FEA) was applied through 3D model to simulate the deep drawing process. The material modeling was implemented utilizing the ABAQUS/EXPLICIT program with plastic anisotropy. The optimization results showed that the deep drawing force and the wrinkling decrease when compared with experimental and numerical results from the literature.


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