Nano-silver paste is considered one of the most promising die-attach materials for high-temperature applications contributing to its excellent thermal and electrical properties and low bonding temperature. However, it...
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Nano-silver paste is considered one of the most promising die-attach materials for high-temperature applications contributing to its excellent thermal and electrical properties and low bonding temperature. However, it is difficult to measure the thermal conductivity and electrical resistivity of nano-silver in practical applications. In this work, we proposed a finite element modeling method to predict the thermal conductivity and electrical resistivity of nano-silver. Nano-silver flake and film with different porosity were prepared by adjusting the sintering temperature, and the thermal and electrical properties were measured. The simulated results are in good agreement with the experimental results under all porosity. The error values between the experimental and simulated temperatures are less than 10%. With the increase of porosity, the thermal conductivity of nano-silver decreases and the electrical resistivity increases. Pores will cause heat flow and current concentration, and increase the possibility of failure of nano-silver in practical applications. The results indicate that the porosity plays a more important role in the thermal and electrical properties of the nano-silver compared with pores location.
The compression performance of a degradable ureteral stent is analyzed and the parameters are optimized by a finiteelementmodeling *** degradable ureteral stent explored in this paper is developed from poly(glycolic...
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The compression performance of a degradable ureteral stent is analyzed and the parameters are optimized by a finiteelementmodeling *** degradable ureteral stent explored in this paper is developed from poly(glycolic acid)(PGA)and poly(lactic-co-glycolic acid)(PLGA)degradable *** on the actual measurement of fabric structure parameters,the three-dimensional model of the stent is established with the help of the modeling *** finiteelement analysis software is used to simulate the compression process of the degradable ureteral *** parameters of materials,interactions and boundary conditions are set according to the compression environment of the stent for modeling and *** this basis,the friction coefficient of yarns,the yarn radius,and the braided angle of the stent are further *** comparison test is carried out by a single *** experimental results show that the change of yarn friction coefficient has little influence on the compressive stress,while the yarn radius and the braided angle of the stent have a great influence on the compressive stress.
In general, amphibious aircraft is subjected to challenges with liquid water freezing to the tires or atmospheric air-cooled icing in low-temperature environments. A finite element modeling method for aviation tires w...
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In general, amphibious aircraft is subjected to challenges with liquid water freezing to the tires or atmospheric air-cooled icing in low-temperature environments. A finite element modeling method for aviation tires was proposed in this study in accordance with LAGRANGE mesh coupling curtain and rubber to investigate and evaluate the tires' icing adaptability of amphibious aircraft and ensure landing safety. The accuracy of the model was verified through simulation calculation, and the shape dimension achieved the maximum error of less than 1.7%. The dynamic response of the vertical ground impact for ice-free and ice-overlaid tires and that of the ground impact of tires during grounded skidding were simulated and analyzed through explicit dynamic analysis. The results of the simulation analysis suggested that the size of ice fragments showed a positive correlation with the ice thickness, and residual broken ice in the tread groove led to local stress concentration in the tread. And the tread rubber stress of the ice-overlaid aircraft tire of this type was less than the tensile strength of 27.8 MPa in the landing process, thus conforming to the required standards. Moreover, a friction-time curve was plotted to examine the impact of tires on the friction force during landings.
The expanding market of new energy vehicles has raised an urgent demand for battery safety. As a crucial component of pouch batteries, the performance of aluminum-plastic film directly impacts the overall safety of th...
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The expanding market of new energy vehicles has raised an urgent demand for battery safety. As a crucial component of pouch batteries, the performance of aluminum-plastic film directly impacts the overall safety of the battery. This paper conducts a macro-level study on the mechanical performance of aluminum-plastic film and presents a comprehensive modelingmethod for simulating the film's behavior. Since aluminum-plastic film is a thin membrane material, conventional methods for measuring material fracture parameters are not applicable. To address this issue, the paper designs a series of experiments using simulation techniques and obtains calibrated parameters for the ductile fracture criterion of the aluminum-plastic film. Consequently, a simulation model is developed to accurately represent the fracture characteristics. The simulation results effectively reflect the actual mechanical properties and fracture behavior of the aluminum-plastic film.
A simplified finite element modeling method for structural cables on bending and wire sliding problems are proposed and formulated. The model is characterized by a beam-spring composition that uses helically arranged ...
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A simplified finite element modeling method for structural cables on bending and wire sliding problems are proposed and formulated. The model is characterized by a beam-spring composition that uses helically arranged short-beam elements to simulate spiral wires, radially-placed rigid beams to replace wire sections and spring elements to capture contact extrusion and friction between adjacent wires. Winding and contacting patterns for semi-parallel wire cables and spiral strands are discussed and then used to formulate the model establishments. In semi-parallel wire cable, any selected wire section can be simplified as a seven-node set to represent the center wire and the surrounded six contact spots. While in spiral strand, wire section can be replaced by four rigid beams that connect the four contact points to wire center. Helical wire compression, sheath pinch effect and contact friction are all considered and calculated, and then bending simulations are conducted on large dimension cables with different end conditions, wire constructions and pretension levels. Simulation results are compared to the test data, and prove that the proposed model can well predict the bending behavior and the varying trend of flexural stiffness. Both cables all express a bilinear elastic-plastic like flexural strength-deflection response. Semi-parallel wire cable has sinusoidal deflection out of the bending plane, and the range of bending gradient is influenced by the cable end conditions. Galfan strand shows little unwinding and torsion effect due to the canceling out effect from alternative twisting between adjacent layers. The model can efficiently simulate long and large dimension cables in a short time, implying its promising applicability in cable studies. (C) 2016 Elsevier Ltd. All rights reserved.
Machining simulation is one of the important applications of computer simulation in modern mechanical manufacturing industry. It is of great significance to produce quality parts more quickly and economically. Modelin...
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Machining simulation is one of the important applications of computer simulation in modern mechanical manufacturing industry. It is of great significance to produce quality parts more quickly and economically. modeling is the key aspect of machining simulation, and it is also one of the vital criteria to the simulation system evaluating. Up to now, there are three existed modelingmethods to machining simulation mainly, which are analytical modelingmethod, finite element modeling method and molecular dynamics modelingmethod. The principle and status of those methods are introduced in detail, and their advantages and current limitations are discussed as well. Then, the developing trend of modeling technology to machining simulation is presented.
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