Amount Of Deformation Research Articles

Design, construction and test of a prototype coil with demountable CuBe joints for pulsed table-top tokamaks

In a classic small tokamak, the magnetic confinement is achieved by toroidal coils that fit into a donut-shape mechanical structure. To facilitate their handling and maintenance as well as the access to various auxiliaries components, their design has evolved toward a modular configuration. For such demountable design, it is important to guarantee the electrical continuity of the winding of the coil across the modular parts through electrical contacts. The resulting joints rely on pressure and specific materials to transfer high current densities at a good mechanical stability and manageable losses. In the present work, a prototype of a circular demountable toroidal field coil (CDTFC) was designed and built to test some technical choices to be used in the final coils of a table-top tokamak referred to as TPM-1U. For this small tokamak, the magnet wires to wind the toroidal coils should be able to handle large pulsed currents in the tens of thousands of Amperes whereas the coil joints should handle a peak current density of at least 75 kA/cm2. The case study here is the TPM-U1 table-top tokamak. Its conceptual design is recalled and mechanical and magnetic details of the demountable coil prototype are provided. For the experimental test, the contacts were slightly pressed using a custom-made contact assembly and current pulses between 4 kA and 8 kA were fedto the coil prototype. The degradation of the joint was visually estimated by assessing the amount of micro-melting, plastic deformation and oxidation appearing at the interface between the materials in contact. It is shown that the selected AWG-04 magnet wire is appropriate for carrying kiloAmpere range pulsed currents and that the CuBe contacts are able to withstand current densities larger than the specification, up to 263 kA/cm2, under low contact pressures of a few mega-Pascal simplifying their handling. Some technical choices have been probed on a prototype coil yielding a generic sequence of tasks to build and test mechanically and electromagnetically demountable coils and their joints.

Prediction of water inflow and analysis of surrounding rock stability in unfavorable geological mountain tunnel

During the construction of a mountain tunnel, water inflow and rock instability are common occurrences due to unfavorable geological conditions, posing serious threats to construction safety. This study focuses on a proposed mountain tunnel and employs multiple formulas to predict potential water inflow during excavation. Based on the amount of water inflow and deformation of surrounding rocks, comprehensive determinations are made for the thickness of grouting rings and permeability coefficients. The results demonstrate that: 1) Different formulas yield slightly varied outcomes but overall trends remain consistent; considering various calculations, the normal water inflow for this tunnel is approximately 115.5908×103 m3/d with a maximum at 210.9100×103 m3/d 2) Increasing grouting ring thickness or decreasing permeability coefficient can effectively reduce water inflow, but the reduction range is gradually narrowed. 3) Pre-grouting curtains have an evident effect in enhancing stability; however, their effectiveness decreases with increased thickness. 4) Taking into account both safety and economic factors, it is recommended that the grouting ring thickness be set at 8 m with a permeability coefficient equaling one 100th that of surrounding rocks for this tunnel project.

A virtual simulation approach to assess the effect of trocar-site placement and scar characteristics on the abdominal wall biomechanics

Analyses of registries and medical imaging suggest that laparoscopic surgery may be penalized with a high incidence of trocar-site hernias (TSH). In addition to trocar diameter, the location of the surgical wound (SW) may affect TSH incidence. The intra-abdominal pressure (IAP) exerted on the abdominal wall (AW) might also influence the appearance of TSH. In the present study, we used finite element (FE) simulations to predict the influence of trocar location and SW characteristics (stiffness) on the mechanical behavior of the AW subject to an IAP. Two models of laparoscopy patterns on the AW, with trocars in the 5–12 mm range, were generated. FE simulations for IAP values within the 4 kPa–20 kPa range were carried out using the Code Aster open-source software. Different stiffness levels of the SW tissue were considered. We found that midline-located surgical wounds barely deformed, even though they moved outwards along with the regular LA tissue. Laterally located SWs hardly changed their location but they experienced significant variations in their volume and shape. The amount of deformation of lateral SWs was found to strongly depend on their stiffness. Trocar incisions placed in a LA with non-diastatic dimensions do not compromise its mechanical integrity. The more lateral the trocars are placed, the greater is their deformation, regardless of their size. Thus, to prevent TSH it might be advisable to close lateral trocars with a suture, or even use a prosthetic reinforcement depending on the patient's risk factors (e.g., obesity).

Tunnel construction in shallow soft rock using the pipe shed support

In order to clarify the impact mechanism of shallow buried soft rock tunnel excavation on the upper existing highway, as well as the mechanism of pipe shed reinforcement, a combination of theoretical analysis and on-site monitoring was used to conduct in-depth research on the Diantou Tunnel Crossing the existing highway project of Dayong Expressway. The impact of shallow buried soft rock tunnel crossing construction on the existing highway and safety control issues were studied, a new deformation control index, namely deformation difference rate, was introduced. The results show that the main lateral area of influence of rock deformation is within a distance of one diameter, and the overall area of influence is within a distance of twice the diameter. From the perspective of axial tunnel deformation, the deformation of surrounding rock tends to be stable when the excavation face passes through the monitoring section about twice the tunnel diameter. Effectively controlling rock deformation depends on the total amount of settlement deformation, the change rate of deformation, and the difference rate of deformation. For V-class shallow buried tunnel surrounding rock, in order to prevent cracks on the surface, the cumulative deformation of the surrounding rock needs to be less than 50 mm, the change rate needs to be less than 3 mm/day, and the difference rate needs to be less than 5 mm/m. Finally, the proposed control standard for surface subsidence is given for similar engineering reference.

Effect of a Gradient Temperature Rolling Process on the Microstructure and Mechanical Properties of the Center of Ultra-Heavy Plates

As there is a small amount of deformation in the center during the rolling process of ultra-heavy plates, it is extremely easy to cause poor mechanical properties in the center. Increasing the deformation in the center is the most feasible method to eliminate the deformation effects in the cross-section of ultra-heavy plates. In this study, the gradient temperature rolling (GTR) process is compared with the traditional uniform temperature rolling (UTR) process. It is found that the GTR process can significantly increase the deformation in the center and thereby refine the grains.. The room temperature tensile test and instrumented Charpy impact test are used to test the strength at room temperature and impact energy at low temperature. Combined with the obtained impact load/energy displacement curve, the deformation and damage process under impact load are analyzed. The microstructure morphology and impact fracture obtained by different rolling processes in the center are analyzed by experimental methods such as OM, SEM, EBSD, etc. The prior austenite grain (PAG) boundary morphology is analyzed and the densities of grain boundaries are statistically quantified. The results showed that the strength, plasticity, and low-temperature toughness of the GTR process are improved compared to the UTR process, with increased dislocation density in the center microstructure, the density of PAG boundaries, and the density of packet boundaries. The size of the PAG in the center is refined by ~49%, the density of PAG boundaries increased by ~140%, the density of high-angle packet boundaries increased by ~39%, and the density of low-angle packet boundaries increased by ~49%. The crack propagation in the instrumented Charpy impact test of the GTR process showed stable expansion, indicating a ductile fracture compared to the semi-brittle fracture of the UTR process. The densities of PAG boundaries and high-angle packet boundaries are the most important factors affecting the strength and low-temperature toughness.

Heterogeneous Microstructure Provides a Good Combination of Strength and Ductility in Duplex Stainless Steel

SAF2507 duplex stainless steel (DSS) is often used as a structural component in ocean-going vessels and marine petroleum exploitation equipment, which require superior mechanical properties. In this study, we used cold rolling (CR) at room temperature with 55% or 80% deformation amounts and subsequent annealing at 1273 K in 1 min to prepare SAF2507 samples with a heterogeneous structure (HS) that was composed of ferrite and austenite phases with different grain sizes. Compared with the homogeneous structure samples, the yield strength of the HS samples increased, while the ductility did not decrease. The 55%-1273 and 80%-1273 samples exhibited the hetero-zone boundary-affected regions on both sides of the grain boundary, phase boundary, and twin boundary. This resulted in hetero-deformation-induced (HDI) strengthening and strain hardening of samples during tensile deformation, which improved the ultimate tensile strength of the HS samples while maintaining a good uniform elongation. In addition, the heterogeneous structure of DSS had better corrosion resistance than the initial sample of coarse grain (CG) structure; mainly because the HS samples had finer grains and more grain boundaries on the DSS surface than the CG structure, which is conducive to the formation of high-density passivation film on the surface of stainless steel. The current study provides a new method of material selection of some structural components with the demands of high strength and good ductility.

Mechanical response and numerical simulation of liquid soil abutment backfill

The application of a new liquid soil material and the treatment effect of backfilling an underpass tunnel in an airport are studied. The deformation and mechanical properties of liquid soil and conventional soil under load are comprehensively compared and analyzed via a numerical simulation with finite element software. The effects of the buried depth of overlying fill, tunnel height, and traffic load on the backfilling of liquid soil abutment are analyzed. The research results show that under the action of load, the overall deformation and stress distribution of the liquid soil and conventional soil show similar laws. However, liquid soil backfilling has great advantages over conventional soil backfilling in all aspects. Liquid soil backfilling can reduce the deformation and the compressive stress at the corner of the backfilling area by approximately 13% and 15%, respectively. The overburden buried depth has a great impact on the subgrade deformation. In the actual construction, the overburden buried depth should be 1.5 m. Overburden depth has a greater impact on the vertical deformation of the road, the self-weight of the overburden will act as an additional load on the overall roadbed, compared to conventional soil backfill, the overburden depth of 2.0 m conventional soil backfill overall deformation of the overburden depth is about equal to the overburden depth of 1.5 m liquid soil backfill, the use of liquid soil backfill is equivalent to the overburden fill to reduce the additional load of 0.5 m. The height of the box culvert has a greater impact on the stress, but this change is not linear, the actual construction in the case of meeting the specific requirements of use, should try to control in the vicinity of 8.4 m, and at the same time the use of liquid soil backfill can reduce the compressive stress of about 14%. The compressive stress increases first and then decreases with the increase in liquid soil modulus. The liquid soil modulus should be controlled to 180 MPa. Moreover, liquid soil backfilling can reduce the compressive stress in the backfilling area by approximately 25%. The trapezoidal slope of the backfill area is proportional to the deformation amount. Although an obvious correlation with compressive stress exists, the regularity is not strong. Thus, the trapezoidal slope should be set to 1:1 during construction. Traffic load slightly affects the overall deformation and compressive stress of the road. However, the distribution trend of deformation and stress changes obviously under the action of aircraft load. In the actual design, only one load form of aircraft load should be considered.

Shrinkage Deformation of Three Different Light Cure Composite Resin Using Image Correlation Method

The study performed were to measured the amount of shrinkage deformation of resin composites with and without bonding agent. The shrinkage defor mation of three types of composite resin (Ecusphere, Densply, CHARISMA) in cavities was studied using image correlation method. The cylindrical cavity in extracted teeth ( premolors) are to examine the shrinkage behavior on the top free surface. The cavities filled with resin after spreading a bonding agent are irradiated using LED unit, also performed on the cavities without bonding agent. One way analysis of variance and MOIRE analysis were used for statistical analysis. The shrinkage behavior was different in the cavities prepared with and without bonding agent. Polymerization of dental composites is characterized by heterogeneous deformation patterns with variable shrinkage values at different locations within the material.

Effect of O-doping on electronic and optical properties of monolayer MoSe2 under shear deformation.

In this study, the electronic structures and optical properties of the pure MoSe2 and O-doped MoSe2 systems under different shear deformations are calculated based on the first-principles approach. It is hoped to provide new possibilities for the design of novel controllable optoelectronic devices and to provide guidance for the application of MoSe2 in the field of optoelectronic devices. The findings indicate that both pure MoSe2 and O-doped MoSe2 systems are somewhat impacted by shear deformation. The pure MoSe2 undergoes a transition from direct to indirect and then to direct bandgap under shear deformation, but still maintains the semiconductor properties. The bandgap of the doped system changes from a direct to an indirect bandgap at 8% shear deformation. According to the examination of the density of states, we find that the density of states of the pure MoSe2 system is mainly contributed by the Mo-d and Se-p orbitals, and the total density of states of the system after O-atom doping mainly originates from the results of the contributions of the Mo-d, Se-p, and O-p orbitals. Optical property analysis reveals that the conductivity and peak value of the pure MoSe2 system are gradually red-shifted toward the low-energy region with the increase of shear deformation. The dielectric function of the O-doped MoSe2 system is red-shifted in the region of 6~10% shear deformation, and the degree of red-shift rises with deformation amount. The findings demonstrate that the electrical structure and optical characteristics of the O-doped MoSe2 system may be modulated effectively by shear deformation, providing a theoretical foundation for expanding the usage of MoSe2 materials in the field of optoelectronic devices. This study is founded on the CASTEP module in the Materials-Studio software within the first-principles of the density-functional theory framework. The photoelectric properties of the intrinsic and doped systems under shear deformation are calculated using the Perdew-Burke-Ernzerh (PBE) of generalized function under the generalized gradient approximation (GGA). The Monkhorst-Pack special K-point sampling method is used in the calculations, and a 5 × 5 × 1 K-point grid is used for the calculations with a plane-wave truncation energy of 400 eV in the optimization of the structure of each model. After geometrical optimization, the energy convergence criterion for each atom is 1 × 10-5 eV/atom, the force convergence criterion is 0.05 eV/Å, and a vacuum layer of 20 Å in the c-direction is set.

A Novel Multidimensional Tensile, Shear, and Buckling Sensor for the Measurement of Flexible Fibrous Materials.

To meet the complex and diverse demands for low-stress mechanical measurements of fabrics and other flexible materials, two integrated multidimensional force sensors with the same structure but different ranges were explored. They can support both rapid and precise low-noise, high-precision, low-cost, easy-to-use, reliable, and intelligent solutions for the complex measurement of fabric mechanics. Having analysed the mechanical relationship of the parallel beam theory, and considering the specific requirements of fabric measurement, a novel multi-dimensional force sensor is designed, capable of measuring tensile, shear, and buckling properties. Finite element analysis is used to simulate the mechanical performance of this sensor for fabric-loading/unloading measurement, and the sensitivity of the mechanical quantity transfer, the amount of sensor deformation, the stress distribution, and the degree of inter-dimensional coupling have been investigated and verified. The basis for subsequent digital processing is achieved by a low-offset, low-temperature-drift, low-power-consumption analogue front end, 24-bit ADC circuit, and signal conditioning electronics, suitable for the measurement of fabric mechanics under low stress, which is like the end-user requirements. The sensor information channel is supported by a host microcontroller with a DSP and a floating-point processing instruction set. Information processing is performed in time-sharing with the support of a multitasking real-time operating system. The purpose of designing this sensor is to facilitate the development of a new testing instrument, which will adopt the advances of current instruments whilst eliminating their shortcomings.

Effect of Hot Deformation on Microstructure and Porosity of Additively Manufactured 7050 Al Alloy

Wire arc additive manufacturing technology of 7050 aluminum alloy has a broad application prospect in aerospace field. But the lack of comprehensive properties caused by coarse columnar grains and pores becomes an important bottleneck. In this study, hot compression is conducted to simulate forging process to investigate the microstructure improvement of as‐deposited 7050 Al alloy by plastic deformation. The effect of temperature at 390–540 °C and deformation at 20%–60% on the microstructure and porosity is revealed. In the results, only slip deformation occurs at 420 °C and below. Local dynamic recrystallization occurs at columnar grain boundaries at 450 °C. Complete dynamic recrystallization occurs at 480 °C with the average grain size of about 60 μm. The microstructure overburns at 510 °C and above. The η eutectic phases are broken during deformation. The hot deformation accelerates the dissolution of η eutectic phases and the dissolution temperature of nano‐phases is 30 °C lower than solid solution. As the deformation amount increases from 20% to 60%, the deformation gradually extends from interlayer to inner of columnar grain layers. The spherical pores are first compressed to ellipsoid and then further compressed until completely closed. The pores are basically annihilated completely at 60% deformation with porosity of less than 0.1%.

Experimental studies of thermo-mechanical characteristics of nitinol alloy springs

The article deals with the research of heat-sensitive elements based on Nitinol material - a wire with a diameter of 1.0 mm, which in the form of springs can potentially be used with the appropriate geometric parameters in the design of a heat engine of an electric power generation system. Research allows to determine the thermomechanical characteristics of springs from this alloy, namely the study of the influence of the magnitude of the preliminary deformation of such elements on the generated force. Heat hardening of the nitinol wire was carried out at a temperature of 400 to 500 °C for 4.5 hours. The study of thermomechanical characteristics was carried out when heating a thermosensitive element (spring) in water from a temperature of 20 °C to 100 °C, force measurements were performed with a spring dynamometer. Thermosensitive elements - two springs made of Nitinol alloy - were chosen for research in this work. The paper shows the model and general view of the experimental setup for the knowledge of thermomechanical characteristics of springs. The thermomechanical characteristics of the springs at different amounts of their deformation have been constructed. Graphs are presented that show that the functional dependence of the maximum generated force on the amount of spring deformation is close to linear. The interpolation method was used in the work, the corresponding coefficients were calculated and the functional dependence was constructed. The resulting dependence allows you to increase the limits of determining the maximum generated force from the amount of spring deformation and will be necessary when modeling the characteristics of a heat engine. Experimental studies have established that a significant influence on the amount of force generated by a spring made of Nitinol alloy is determined by the amount of spring deformation. At a spring deformation of 160 mm and a temperature of 100 oC, the generated force was 4...4.05 N, and at a deformation of 100 mm - 1.75...1.85 N.

Cryo-compression and annealing hardening of 7075 aluminum alloy

7075 aluminum alloy, as a lightweight, high-strength, and corrosion-resistant structural material, is widely used in the aviation industry. Because 7075 aluminum alloy is commonly used in structural components, its plastic processing ability is highly required by the usage environment. Recent studies have shown that 7075 aluminum alloy exhibits better deformation ability under low temperature conditions. In this paper Cryo-compression experiments on 7075 aluminum alloy under different compression rates (0.001 s-1-0.5 s-1) in a low-temperature environment (soaked in liquid nitrogen for 30 minutes) has been discussed. Annealing process research was conducted on the low-temperature compressed samples, and the optimal annealing process parameters (400Co, insulation for 15 minutes) and optimal deformation amount (16%) were obtained through comparison of microstructure and properties. And it was found that 7075 aluminum alloy exhibited annealing hardening phenomenon when annealed at 250 Co, and the reason was the diffusion segregation of solid solution elements formed during low-temperature forming, which led to the precipitation of the second phase MgZn2 during low-temperature annealing.

Numerical analysis on the deformation of scroll teeth of variable base circle radius scroll expander

For research on the effect of different working loads on the deformation of variable base circle radius scroll expander scroll teeth, a multi-field-coupled calculation method is proposed to reveal the deformation law of scroll teeth under different working loads. In this paper, the equations of the variable base radius profile are derived using the normal isometric method to establish a three-dimensional model of the variable base radius scroll expander. The CFD dynamic mesh technique is used to simulate the working process of a variable base radius scroll expander to obtain the flow field variation in the inner part of the working chamber. The results of the simulation are applied to the scroll teeth by interpolation to analyze the deformation of the scroll under single-field loading and multi-field coupling, to obtain the deformation law of the scroll teeth. The results of the study show that the deformation of the scroll teeth does not decrease linearly with the involute spreading angle from the head to the tail of the teeth due to the uneven temperature distribution of the scroll expander. The thermal stress of the temperature load impacts the deformation trend and amount of the scroll tooth, whereas the gas force load just modifies the amount of scroll tooth deformation and has a lower effect on the scroll tooth's deformation trend. Under different loads, the same deformation and different deformation on the scroll teeth can interact with each other to reduce the scroll tooth deformation to a certain extent.

Design and characterization of LaB6/NbNiTaTi refractory high-entropy alloy coatings: Effect of in-situ TaB phase on strengthening mechanism

The excellent strength and hardness obtained from the customized phase compositions provide vast spaces for surface protection application of refractory high entropy alloy (RHEA) coatings in titanium alloys. However, the introduction of high-strength brittle phase in RHEA coatings commonly increases the cracking tendency and affects their service life. In this work, we propose a design strategy to enhance the mechanical properties of RHEA coatings by introducing an extremely stable high strength boride combined with a ductile phase. Experimentally, LaB6/NbNiTaTi RHEA coatings mainly consist of BCC phase, in-situ TaB phase and NiTi/IM eutectic phase. TaB phase with high-density (110) nanotwins inside presents needle-like morphology with the long side axis parallel to the [001] direction. Excessive needle-like TaB phase is fully fused and fractured due to its preferential growth along a specific direction. The fracture surface analysis shows that BCC phase bears the main deformation, NiTi phase can relieve stress concentration at the boundary while bearing a small amount of deformation. By contrast, the low-density dislocation distribution and the low energy extended dislocation structure in TaB phase exhibit the phase stability. In addition, the amorphous islands are formed near the high-deformation regions when the defect concentration reaches the critical value.

Determination of the dependencies of the wear influence of the cylindrical brush on the operational characteristics of the garbage truck’s mounted sweeping equipment

The article is dedicated to the establishment of dependencies of the influence of the wear of the cylindrical brush on the operational characteristics of the mounted sweeping equipment of the garbage truck. By using the planning of the second-order experiment with the first-order interaction effects, using the Box-Wilson method, the adequate dependencies of the influence of the wear of the cylindrical brush on the performance characteristics of the mounted sweeping equipment of the garbage truck were determined. It was established that, according to the Student's criterion, among the investigated factors of influence, the wear of the cylindrical brush has the greatest effect on the deformation of the cylindrical brush, and the width of the contact spot has the least influence. The required pressing force of the cylindrical brush is most affected by the width of the contact spot, and the least by the wear of the cylindrical brush. The response surfaces of the target functions are shown – the amount of deformation and the required pressing force of the cylindrical brush and their two-dimensional cross-sections in the planes of influence parameters, which make it possible to visually illustrate the specified dependences of target function data on individual influence parameters. It was established that the wear of the cylindrical brush of 50% of cases leads to an increase in the deformation of the cylindrical brush by 1.3 times, and the necessary force of pressing of the cylindrical brush – by 3.1...3.6 times, depending on the width of the contact spot. It is shown the expediency of conducting further researches of the effect of antifriction materials on the wear of the friction pairs of the mounted sweeping equipment of the garbage truck.

Microstructure evolution, mechanical response and strengthening models for TA15 titanium alloy during thermal processes: A brief review

TA15 titanium alloy is widely used in aerospace industry in terms of its high specific strength, good thermal stability, and excellent corrosion resistance. To further improve its mechanical properties, thermal deformation combined with heat treatment is always used, during which the microstructure evolution and mechanical response are absolutely complex leading to the difficulty in control of final mechanical properties. Therefore, in-depth research on the relationship between microstructure and mechanical response of TA15 titanium alloy during these processes is of great significance. At present, less relevant review has been reported. In this article, the effects of process parameters such as heating temperature, strain rate, deformation amount, deformation mode, deformation path, cooling method and soaking time on the microstructure and mechanical properties of TA15 alloy, namely tensile performance and damage tolerance properties have been discussed. In addition, some strengthening models suitable for TA15 titanium alloy have been analyzed. In conclusion, different microstructure morphologies formed in various processing processes will display diverse mechanical performances in which the direct relationship between the yield strength and microstructure morphology can be established through distinct calculation models but with some limitations. So, in future works, microstructure and mechanical properties should be optimized further through adjusting processing parameters. Moreover, strengthening models remains to be modified by adopting more accurate statistical methods and considering more factors. Finally, establishing the relationship between damage tolerance properties such as fracture toughness, creep performance and LCF property and microstructure features should be considered more for TA15 alloy.

Variability of quaternary marine terraces and uplift rates in the Andean coastal zone at 23°S

During the Quaternary most of the coastal areas along the Andes were uplifted due to subduction related processes. At 23°S, along the Mejillones Peninsula and the shoreline of the Coastal Cordillera, there is an abundance of Quaternary marine terraces, coastal cliffs, eroded dikes, alluvial fans, and fault scarps which preserve evidence of this uplift. The hyper-arid conditions have minimised subaerial erosion to the extent that the Quaternary marine terraces (QMT) can be carefully studied to understand the amount of permanent deformation in the forearc and the variability of uplift rates along the coast. A morpho-metric analysis using remotely sensed imagery from ALOS-PALSAR, drone survey and local differential GPS data allowed us to define the best-preserved QMT sequences and the elevation at which they were found with respect to the modern mean sea level. We propose a correlation between the individual paleo-shorelines of each marine terrace with a Quaternary Marine Isotope Stage (MIS). We determined two representative areas with well-preserved marine terraces: Morro Mejillones, in the western zone of the Mejillones Peninsula (∼12 × 10 km2) and the combined Hornitos – Punta Chacaya zone (∼16 × 7 km2), in the northern part of the Mejillones Bay. Within these areas we identified 12 QMT's in Morro Mejillones with estimated uplift rates between 0.31 and 0.76 m/ka over the last 600 ka, 3 QMT's In Hornitos with uplift rates between 0.28 and 0.4 m/ka over the last 220 ka, and 4 QMT's in Punta Chacaya with uplift rates between 0.25 and 0.39 m/ka over the last 330 ka. We link differences in uplift rates as related primarily to the distance from the coastal zone to the subduction trench and, locally, to their variable location with respect to faults active during the Quaternary.

Parametric studies and compressive performance of GH4169/K465 Kagome lattice structure prepared by selective laser melting

This paper is proposed a sufficient strategy to enhance the Kagome lattice structure by introducing sphere connections at the joints of the rods. Three types of lattice structures, namely single-cell Kagome, sandwich monocyte, and multi-layer sandwich GH4169/K465, were fabricated through the selective laser melting method. Experimental results demonstrated that the load peak value of the lattice structure increased gradually with variations in rod diameter and angle. When the rod diameter is 2 mm and the angle is 50°, the comprehensive performance is relatively excellent. Both the single-cell Kagome and sandwich monocyte structures exhibited a secondary load peak curve for the load versus displacement curve.The primary failure mode of the spherical connections Kagome structure is member fracture. For sandwich cell structures, when the rod diameter is 1.1 mm, the elastic modulus, yield strength and energy absorption of SRK are 412 MPa, 17.02 MPa and 8.05 MJ/mm3, respectively. When the rod diameter is increased to 1.7 mm, the properties of SRK are 561 MPa, 84.32 MPa and 35.49 MJ/mm3, respectively. The properties of SRK gradually increase with the increase of rod diameter. the elastic modulus, yield strength, and energy absorption of strut-reinforced Kagome with varying rod diameters surpass those of both the Kagome and spherical connections Kagome structures. The failure mode in strut-reinforced Kagome structures is primarily due to rod buckling. In the compressive stress-strain curve of the multi-layer sandwich structure,when the deformation amount is 0.2, SRK has a higher compressive strength than Kagome and SCK structure, which can reach about 350 MPa, while Kagome and SCK are lower than 200 MPa. demonstrated a gradual increasing trend in stress with increasing strain. In addition, the mechanical properties of the Kagome lattice structure are enhanced due to partial structural failure, with fracture occurring in certain members.

Development of High-Entropy Shape-Memory Alloys: Structure and Properties

Amongst functional materials, shape-memory alloys occupy a special place. Discovered in the beginning of 1960th in XX century, these alloys attracted quite an attention because of the possibility to restore significant deformation amounts at certain stress–temperature conditions due to the martensitic diffusionless phase transformation involved in a process. It was possible to exploit not only so-called ‘shape-memory’ effect, but also superelasticity and high damping capacity. Over the years, more than 10 000 patents on shape-memory alloys were filed, appreciating not only the possibility to exploit energy transformation to ensure the response (feedback) at the change in independent thermodynamic parameters (temperature, stress, pressure, electric or magnetic field, etc.), but the significant work output as well. Applications ranged from different gadgets to automotive, aerospace industries, machine building, civil construction, etc. Unfortunately, the structural and functional fatigue restricted successful business application to medical sector with nitinol shape-memory alloy (different implants, stents, cardiovascular valves, etc.). Emerging high-entropy shape-memory alloys can be considered as a chance to overcome fatigue problems of existing industrial shape-memory alloys due to their specific structure that ensures superior resistance to irreversible plastic deformation.