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This paper provides a connection between an industrial problem of the maximization of aircraft utilization and maintenance cost savings. A more flexible structure is proposed to perform the maintenance not only during scheduled periodic checks but also whenever the aircraft is on the ground for any reason. The proposed method is the use of the single task-oriented maintenance concept. The results...
Magnetic levitation planar motor was researched and developed for vacuum compatibility. Laser interferometers are used in order for high precision measurement. However, the magnetic levitations cannot experience full working range due to the high sensitivity of the laser interferometers. Especially, angular alignment is important for laser interferometer to measure the motions. In this paper, a cause...
The modified resin system of 4, 4'-bismaleimidodiphenylmethane ((BDM)/ortho-diallyl bisphenol A(DBA)(BMI)/reactive groups-terminated polyethersulfone (rPESU) (BMI/P)was prepared by melting pre-polymerization. Typical properties (The gelation time, mechanism, phase structure and thermal stability) of the BMI/P resin were systematically investigated, and their origins were discussed. The results show...
An analytical solution and numerical models are proposed for the buckling and post-buckling behavior of honeycomb sandwich structures under edgewise compression. General buckling and core crushing due to transverse shear are observed in the experiment. Based on these phenomena, the von Kármán plate theory are employed for the analysis for the buckling behavior and the analytical solution for the core...
The analysis of three-dimensional (3D) braided composites is difficult due to its complex microstructure. A novel representative unit cell (RUC) and shear specimen model is introduced to predict elastic properties and failure behavior of 3D 8-harness satin weave composites fastener under shear load. The RUC model is developed to predict engineering constants of composites in several damage status...
A brake assembly piston rod from a RAAF aircraft had fractured as a result of tensile fatigue that had initiated within a relatively pronounced machining mark at the change in section from a stress relief groove to piston rod body. While cracking could be detected under Scanning Electron Microscope (SEM) examination, crack width was such that high sensitivity fluorescent dye penetrant inspection methods...
The purpose of this paper was to investigate the damage tolerance of single-stiffener panels. The impact response and the influence of impact damage on compression behavior were studied. Barely visible impact damage (BVID) was introduced to the stiffener flange tip on the smooth side. By applications of visual inspections and C-scan, massive damage was detected. After the impact experiment, compression...
For composite structure design, determining the relationships between failure time and mechanical properties in the full range of working temperatures is essential. Dynamic mechanical analysis (DMA) and tensile tests were performed to get the dynamic and static mechanical properties of resin 5228A respectively at various temperatures. The master curves of storage modulus and Young's modulus were constructed...
Compression is a design limiting for composites as its much lower strength than tension. And it is still a challenge to predict the damage process for open-hole composite laminate under compression precisely Therefore, we proposed a progressive finite element model to demonstrate the failure behavior of open-hole laminates under compressive loading(OHC) for high-modulus and high-strength fiber reinforced...
The heat transfer coefficients (HTC) on the surface of a copper disk sample during a quenching operation have been studied here. The sample is made very small so that the lumped mass approach can be applied for the measurements. Lumped heat capacitance is one of the technique, which is advantageous due to its simplicity, but it is an approximate technique to determine the HTCs, as this method assumes...
In this research, first, a method of adhering a minute amount of adhesive, that is, microbonding method of adhesives, has been investigated, and a 2DOF(degree-of-freedom) pantograph mechanism for realizing the microbonding is described. Second, a polymer-made hinge made of polypropylene is proposed, and two kind of 2DOF pantograph mechanisms including polymer-made hinges and links are developed to...
Electrochemical Machining (ECM) is an outstanding method to process micro-scale products for its fine surface quality and non-residual stress remaining after machining. This study proposes a sliding Electro Chemical Machining (SECM) method to fabricate tungsten carbide micro fins. The method was expected to thin the pre-machined tungsten carbide fins into micro scale. During conventional ECM process,...
In recent years use of image processing techniques for texture analysis of machined surface is gaining importance in the field of manufacturing. This manuscript addresses texture identification methodology using Wavelet transform and artificial intelligence techniques. Captured images of machined surface using Electric discharge machining, milling, sand blasting and shaping is decomposed in to sub...
The paper overviews the principle and technological processes of chemical vapor deposition rhenium, iridium and niobium for high performance Re-Ir thrust. The CVD technology has predominance at manufacture of Re-Ir thrust chamber due to the conformality during deposition process. Uniformly depositing control and guarantee of high performance of the deposited for CVD rhenium process, purity improvement...
The performance characteristics of kagome lattice truss core sandwich panel made of TC4 titanium alloy has been investigated in this paper. The sandwich panel was fabricated using 3D printing technology and test in out-of-plane compression. The compressive stiffness and the maximum capacity of compressive load were obtained through experiments. The plastic bending deformation of the strut members...
Warm sheet hydroforming process has being investigated in recent years with its high formability feature. Warm hydromechanical deep drawing (WHDD) which is a type of the warm sheet hydroforming process is important for deeper parts. To determine the formability of the WHDD process the most convenient tool is Limiting Drawing Ratio (LDR). But determination of the LDR accurately needs using of the most...
In this research, the body of a sheet hydroforming press, which can produce an industrial product, was designed and dimensioned. Initially, the required pressure and forces to produce the industrial product were determined by finite element analysis. Then, structural analysis of the press body was conducted by using these forces in Solidworks Premium simulation module. The strain gauges were bonded...
The present study deals with optimization of machining characteristics using Multi characteristic Optimization in collaboration with utility concept. Surface roughness & Tool wear rate are the selected response characteristics for investigation. The study makes use of Taguchi's robust design experiments with Utility concept. Each experiment was conducted using different combinations of input parameters...
Annular thermosyphon or ATS was made from three concentric tubes with difference in diameter. An annular passage lying between an inner tube and a middle tube was evacuated and filled in with working fluid; therefore, a function of this annular passage was identical to that of the passage inside of ordinary thermosyphons. In order to assess possibility to apply the ATS on practical heat transferring...
The paper focuses on the problem of crack formation in an infinite strip with free sides as a result of residual stress relief. The formulas for residual stresses and for the corresponding displacements have the form of series in Papkovich-Fadle eigenfunctions. The coefficients of the series are determined in a simple closed form by means of functions which are biorthogonal to Papkovich-Fadle eigenfunctions.
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