Papers by Keyword: Three-Dimensional

Abstract: One of the fundamental innovations in the field of mechatronics is the direct material integration of mechanical and electronic functions using Molded Interconnect Devices (MID technology). Unlike conventional circuit boards, they are not limited to two dimensions but offer the possibility to arbitrarily lay printed circuit traces on the surfaces of the 3D carrier, traditional 2D routing function in EDA cannot be directly applied in MID design. In this paper, two new 3D automatic routing methods are introduced. One method is based on a grid graph and extends Hadlock’s minimum detour algorithm; the other is gridless and combines the A*-algorithm and an extension of Hightower’s algorithm. The related 3D routing functions, which are not supported by conventional MCAD und ECAD systems, are integrated in the design system MIDCAD. With these 3D routing functions, MIDCAD enables a more effective product design based on the MID technology.

Abstract: The three dimensional finite element model of composite laminates made of carbon fiber reinforced bismaleimide resin is built, and the stress state of the composite laminates under unidirectional tensile force is analyzed. The strength criterion and damage mode are given based on the stresses of material principal direction. The three dimensional finite element model of the same laminates with non-penetrating damage repaired by scarf bonding method is built, and the stress state is also analyzed. The strength criterion and the damage mode of the scarf bonding composite laminates are also given. The strength and the damage mode of original laminates are compared with that of the laminates with non-penetrating damage. The influence of the interlaminar stress is considered in these analysis models. It is showed that the three dimensional models can simulate the geometric and physical features of the real composite laminates. It is concluded that the original composite laminates made of carbon fiber reinforced bismaleimide resin and the repaired one both damage first in the laminar whose second material principal direction coincides with the axial tensile force. And the damage mode is resin crack under tensile stress. The strength of the bonding patches is higher than the laminates repaired by scarf bonding. After scarf bonding repair, the strength of the damaged laminates can recover up to about eighty-four percent.

Abstract: A new algorithm of phase field model is developed to simulate polycrystalline dendritic solidification growth in undercooled melts. The algorithm adopts a single phase field order parameter model incorporated with the anisotropy of solid-liquid interfacial energy and mobility. The model validation is performed by comparing the simulations with the theory analytical results and experimental information for both single and multi-grain dendritic growth, which demonstrates the quantitative capabilities of the proposed algorithm.

Abstract: The present work focuses on the numerical prediction of the manufacture quality of a sliding panel structure, in which the mobile components are floating on the immobile components and the 0.002mm thickness oil-film clearance between the mobile and immobile components. The interaction between them is the interfacial coupling interaction. A single-point spring-damping supporting element is introduced to simulate this type of interaction traditionally, in which the torsion of the mobile components is increasing with the supporting element reduced. To analogy the interfacial coupling interaction, the finite centrality supporting method is introduced to study the thin oil-film effect between the mobile and immobile components. And the manufacturing quality is predicting through the numerical study. Compared with the results derived from the numerical and experiments, the manufacturing error is in accordance with each other.

Abstract: Based on a thin interface limit 3D phase-field model by coupled the anisotropy of interfacial energy and self-designed AADCR to improve on the computational methods for solving phase-field, 3D dendritic growth in pure undercooled melt is implemented successfully. The simulation authentically recreated the 3D dendritic morphological fromation, and receives the dendritic growth rule being consistent with crystallization mechanism. An example indicates that AADCR can decreased 70% computational time compared with not using algorithms for a 3D domain of size 300×300×300 grids, at the same time, the accelerated algorithms’ computed precision is higher and the redundancy is small, therefore, the accelerated method is really an effective method.

Abstract: Cathode design is a difficult problem must be faced and solved in electrochemical machining (ECM). In ECM process, various parameters, such as applied voltage, current density, gap distribution, machining rate and electrolyte composition and concentration, can affect ECM machining process and therefore cathode design. Among all these machining parameters, gap distribution is the most vital. Regard some type of aero-engine compressor blade as research object, this paper concentrates on the effects of the normal gap distribution of 2-dimension and 3-dimension on cathode design based on the cathode design method of , moreover the errors between two and three dimension normal gap also can be compared and analyzed in detail. To verify the accuracy of the designed cathode, the machining experiments were conducted on an industrial scale ECM machine and the experimental results demonstrates that the cathode designed utilizing 3-dimension normal gap exhibits more machining accuracy and therefore valuable.

Abstract: The mechanism of effect of the acceleration on acceleration sensor is preliminary elucidated. Using the three-dimensional finite element method, the temperature field in sensing element of the sensor under the effect of the different acceleration have been obtained by a series of procedure , such as model building ,meshing ,loads applying and equation solving. In the process ANSYS2FLOTRAN CFD program is applied. By the numerical results and experiments, the effect of input acceleration on accleration sensor is analogous to the effect of input tilt angle on the sensor, which also will change the temperature of gas flow at two thermal resistors ,so lead to change of the current difference of both thermistor wires, finally the bridge outputs a voltage signal corresponding to the acceleration.

Abstract: Following spatial mesh principle, the gear cutting meshing equation was established in the paper through analyzing the relation between the machining principle of the double circular arc profile spiral bevel gear and the movement of the machine tool. The parameters of cutter head and the machine tool’s movement were then obtained through the equation. VERICUT was applied to build the three-dimensional virtual simulation machining model by which the gear geometry parameters, cutter parameters and machining tool movement parameters were calculated for a given gear to be processed and virtual simulation machining proceeded to prove the validity of the model.

Abstract: Combining element free Galerkin method with rigid/visco-plastic flow theory, the paper establishes the three-dimensional rigid/visco-plastic element free Galerkin method, and introduces it to analyze three-dimensional bulk metal forming processes. The velocity field is approximated by MLS method. Employing the incomplete generalized variation principle, stiffness matrix equation and solution formulas are derived. And STL format discrete triangular patches are used to describe the mould cavity. An analysis program for simulating three-dimensional bulk metal forming processes is developed. The program is capable of simulating three-dimensional unsteady bulk metal forming processes with severe deformation and arbitrarily shaped dies. A numerical example is analyzed. Numerical results such as material flow patterns and distributions of the effective stress are obtained. The effectiveness and validity of the proposed method and techniques are demonstrated by comparing with results obtained by using commercial finite element software.

Abstract: A novel electrode of supercapacitor was developed with a three dimensional (3D) structure which results in a significant increase of the electrode area per unit capacitor volume. An area of 2.58 times the area of corresponding planar design was obtained. The process flow for fabricating the 3D electrode was developed compatible with microelectromechanical system technology. The key processes were high-aspect-ratio Deep Reactive Ion Etching, electroless plating and electropolymerization. Ni as the current collector was deposited on Si/SiO2 substrate by using electroless plating, Polypyrrole was galvanostatically polymerized as electroactive film. The capacitance properties of the 3D electrode were investigated. Cyclic voltammetry tests show that the specific capacitance of the 3D electrode at 100 mV/s was 0.014 F/cm2 which is comparable with the 0.013 F/cm2 for the planar design. Electrochemical impedance spectroscopy plot of the 3D electrode is well fitted by equivalent circuit, we found the specific capacitance is 0.011 F/cm2 which is slightly larger than 0.0094 F/cm2 for similarly planar design. From the gavanostatic charge/discharge tests, the specific capacitance of the 3D electrode at 2 mA/cm2 is 0.011 F/cm2 while for planar design the corresponding value is 0.010 F/cm2. The results indicate the continuous and homogeneous Polypyrrole film with 3D structure was obtained as we designed.