The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, the interfacial nanoscale bondability between copper (Cu) and Aluminum (Al) intermetallic compound (IMC) for Cu wirebonding has been carefully investigated. Preliminary results demonstrated that IMC cracks from the edge of bonding interface and spreads into the center area. This is the cause of open fail. The IMC between Cu and Al was initially generated in the form of CuAl2, and gradually...
Bird strike, also known as avian ingestion, is the collision between a bird and an aircraft. Bird strikes have always been a cause of worry in the aeronautical industry: Aircraft both old and new have suffered from bird strikes. Jet engine ingestion occurs when the bird hits the jet engine of an aircraft and gets sucked in. Given that the fan blades rotate at a high rpm, bird strike on a fan blade...
In this paper buckling loads and modes of an Euler beam made of graphene are considered. An eigenvalue problem is formulated with an additional parameter representing material's elastoplasticity. Analytical approximate solution using the perturbation method is presented. This approximate solution is used as a basis for an iterative finite difference scheme to develop a more accurate solution. Deflection...
Many of flat rolled products manufacturers are never subjected to a batch annealing practice. Prime high volume examples are AlMnMg (3004, 3014) and AlMg4.5Mn (5182) families of alloys and the similar is used for deep drawn products. If the exit temperature of the last hot rolling pass is high that the material self-anneals, which promotes to form the earing 45° from the earing 90° of the hot rolling...
Vacuum interrupters are now widely used for medium voltage switching up to 38kV in such applications as metal-clad switchgears, circuit breakers, etc. Vacuum interrupter minimizes the damage and loss of the contact points at the optimum zero point of current wave after separation of the contact points, due to its quick vacuum insulation recovery characteristics. The fixed and moving electrodes of...
The reliability of connector is depending on the contact force, generated by the spring in terminals of connectors. The springs are formed by stamping from a strip of spring material. Therefore, the prediction of its springback after stamping and force-displacement relation by the finite element (FE) simulation is important for the design of terminals. The mathematical model of stress-strain (s-s)...
This paper deals with the modeling and position control of an ElectroActive Polymer (EAP) actuator system consisting in a combination of an EAP membrane and a mass-spring biasing mechanism. First, a description of the biasing system is provided, and a physical-based dynamic model is derived for the whole system. Then, the model is used for the identification of an experimental actuator, and for the...
Ball grid array (BGA) has the characters of excellent heat dissipation and high mechanical strength to satisfy with the need of high density packaging of electro produces. However BGA faces some problems of complex viscoplastic deformation, difficult failure test and high repair cost. This paper establishes a complex multichip packaging module with lead-free solder ball SAC305 BGA solder ball based...
The whisker formation behaviors of Sn3.0Ag0.5Cu composite solder which reinforced by an organic-inorganic hybrid materials, silanol of polyhedral oligomeric silsesquioxane (POSS-silanol) was investigated. The thin solder films were obtained by reflow soldering and a thermal cycle from −40°C to +85°C was applied to accelerate the test process. Both surface and interface microstructures of the specimens...
Based on the finite element approach and the strain gradient (SG) theory, this paper produced a study on factors of size effect and minimum cutting thickness phenomenon in the micro-cutting process. Mechanisms of micro-cutting focusing on its characteristics that include size effect, tool edge radius and minimum cutting thickness has been studied. A new constitutive relationship based on SG theory...
The dynamic mechanical properties of Sn-Ag lead-free solders have been studied by means of a split Hopkinson pressure bar (SHPB) at various strain rates. Tests were conducted at room temperature and under uniaxial compressive conditions. It is shown that the Sn-Ag lead-free solders are viscoplastic materials, which are sensitive to the strain rate at higher strain rate. It is found that the materials'...
For the purpose of describing the strongly nonlinear output of Giant Magnetostrictive Material (GMM), the J-A Model and Z-L Model are introduced based on a detailed analysis of the magnetic field intensity distribution inside the GMM stick, and a better dynamic output model is established. The static output properties of the GMM stick are forecasted, the influence of pre-pressure, bias field and exciting...
Rate-dependent behavior together with failure characteristics of carbon/Kevlar hybrid woven composite under high-strain-rate impact loading were examined. High levels of strain rate, 1008/s∼1922/s, tests were conducted on the cylindrical carbon/Kevlar hybrid composite specimen by means of a Split Hopkinson pressure bar (SHPB) and a high pressure gas gun system. The dependence of flow stress on the...
Due to their technological and economical advantage, laser machines are rapidly developed all over the world. Based on the theory of multi-body system (MBS), the error model of a five-axis multi-function laser machine including three slide and two rotating table was discussed. for the purpose of verification of above works, the double frequency laser interface detecting instrument of RENISHAW is used...
Ultrasonic nonlinearity measurements have been suggested as an effective tool for the early detection of fatigue damage in metallic structures. However, the correlation between ultrasonic nonlinearity and material damage induced by fatigue or plastic deformation has been observed to be non-monotonic by several researchers including by our group. To clarify the correlation between microstructure and...
Electromagnetic (EM) radiation can be produced by mechanical excitation for certain elastic materials like piezoelectric material. The problem involves both electrodynamic and elastodynamic processes and the coupled Maxwell's equations and elastic wave equations are generally solved in their partial differential equation (PDE) form. In this work, we develop an integral equation approach for solving...
Reinforced flexible structure, suitable for large deformation, in high grade highway bridge and road junction wide application. Most current engineering construction before, and not to the structure stress and deformation prediction effectively, put forward the construction of guidance. In this paper, ANSYS finite element software, the introduction of contact element, through to the plane strain problems...
In order to monitor curing process of epoxy resin in real time, the system for cure monitoring is established based on Fiber Bragg Grating. First, a bare FBG, a FBG packaged with quartz capillary and an accurate resistance thermometer are closely stacked into a special mould. Then the mould is filled with mixture of epoxy resin and curing agent. Finally they are heated and cured together in the temperature-controlled...
Modeling of various manufacturing processes, including force and power requirements, depends on accurate estimation of a material's flow stress. The paper presents a mutual comparison between rule-based expert system and artificial neural network in predicting flow stress of a commonly used type of steel. The prediction processes take microstructure, applied temperature, strain, and strain rate as...
Angular displacement sensing and contact force sensing in robotic surgery is important for finding the conformation of the tool and for closed loop control. Current techniques for measuring large deflections, such as electromagnetic tracking, involve bulky external reference equipment. This paper discusses the design, dynamic modeling, and kinematic simulation of a compact two-axis bend sensor constructed...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.