Showing papers in "Optics and Lasers in Engineering in 2010"

TL;DR: This paper presents a meta-analyses of Fourier-Transform Profilometry and its applications in 3-D Shape Measurement and Surface Profile Measurement for Structured Light Pattern and 4-Core Optical-Fiber.

TL;DR: The principles of the real-time 3D shape measurement techniques that were developed are presented, the most recent progresses that have been made in this field are summarized, and the challenges for advancing this technology further are discussed.

TL;DR: The basic principles and typical applications of this technique based on grating projected and fringe analysis, which attracts the attention and research effort in the past ten years, has been targeted as main objective to review.

TL;DR: In this article, a simple and easy-to-calculate yet effective global parameter, called mean intensity gradient, is proposed for quality assessment of the speckle patterns used in DIC.

TL;DR: In this article, the microstructure and mechanical properties of 304 stainless steel joints by tungsten inert gas (TIG) welding, laser welding and laser-TIG hybrid welding were investigated.

TL;DR: Phase extraction methods from a single fringe pattern using different transform methods are compared using both simulations and experiments to determine the merits and limitations of each.

TL;DR: In this article, the effect of laser parameters such as fluence, number of shots, and gaseous environments on micro-nano structure formation has been investigated, and it has been shown that arrays of micro/nano holes could be formed in thin Ti foils by direct laser treatment.

TL;DR: Four practical considerations in fringe projection profilometry based 3D shape measurements, along with simple but robust solutions, including gamma correction of digital projection, arbitrary setup of system components, phase unwrapping with multi-frequency fringes, and system calibration with a least-squares inverse approach are presented.

TL;DR: In this article, the authors investigated the influence of shape function, the interpolation order and the subset size on the derived strain fields and showed that the errors can be substantially reduced if conscious choices in the abovementioned implementations are made.

TL;DR: In this article, a reinforced Ti-C carbide nitride (TiCN) reinforced Ti coating was fabricated on the surface of Ti-6Al-4V alloy by laser cladding method.

TL;DR: In this paper, a monitoring system comprising two cameras and a projected laser line is developed for on-line control of the metal-wire deposition process, which is a fairly new technique being developed at University West in cooperation with Swedish industry for solid free-form fabrication of fully densed metal structures.

TL;DR: In this article, the authors compare the potential errors induced by the following factors: degree of defocusing, exposure time, synchronization, and projector's nonlinear gamma, and show that the DBP method is smaller than that of the FSP method.

TL;DR: In this article, a non-contact high-temperature deformation measurement system is established by combining transient aerodynamic heating simulation device with the reliability-guided digital image correlation (RG-DIC).

TL;DR: Numerical simulation results have demonstrated the feasibility and effectiveness of the proposed DFRNT encryption method and the variation in fractional order, the change of Arnold transform iteration number, known-plaintext attack, noise addition and occlusion of the encrypted image, respectively.

TL;DR: In this paper, a laser-heating of Inconel 718 alloy is considered and the resulting temperature and stress fields are predicted using the finite element method (FEM) using an experiment carried out to treat the alloy surface by a laser beam at high pressure nitrogen environment.

TL;DR: FTP, phase-shifting and continuous wavelet transform (CWT) are briefly described and discussed and two-dimensional short-time Fourier transform (STFT) is also presented to extract wrapped phase maps.

TL;DR: In this article, a dual-beam YAG laser with the continuous wave (CW) and pulse wave (PW) modes was used for lap welding of JSC270CC steel and A6111-T4 aluminum alloys.

TL;DR: Two random angle shifts are introduced to rotate the color vectors composed by the three color components in discrete Hartley transform domains in image encryption process, and the corresponding rotation shifts of the two angles can serve as the key of the scheme.

TL;DR: High-definition thin-walled parts of AISI316L are successfully fabricated, and the LS-SVM network is more suitable for the prediction of the DH, although the predicted result by the BP-AM approximates the experimental result, the above performance index of the LS -SVM are better than those of the BP -AM.

TL;DR: In this article, an adaptive approach to fringe-pattern projection was proposed to adjust the maximum gray level based on images acquired during measurement, and calibration parameters determined in earlier calibrations.

TL;DR: In this article, surface carburization of a Ti-6Al-4V alloy using laser melting has been investigated experimentally, with the aim of increasing surface hardness and hence improving related properties such as wear and erosion resistance.

TL;DR: In this article, the microstructure, chemical composition and phase analyses of the cladding layer were studied by scanning electron microscopy, EDX analysis, and X-ray diffraction measurement.

TL;DR: In this paper, errors related to digital image correlation (DIC) technique applied to measurements of displacements are estimated based on the generation of synthetic images representative of real speckle patterns.

TL;DR: In this article, the authors presented parameter optimization of the kerf quality characteristics during pulsed Nd: YAG laser cutting of nickel based superalloy thin sheet, and measured through Tool Makers Microscope.

TL;DR: In this paper, an analytical tool for a nearly continuous analysis of gas-phase polycyclic aromatic hydrocarbons (PAH) based on laser-induced fluorescence was designed and built.

TL;DR: In this article, the authors investigated the origin and subsequent evolution of self-organized conical micro/nano structures in silicon surface upon irradiation of multiple ultrafast laser pulses in the gaseous environments of SF 6 and He.

TL;DR: A modified version of the electronic circuit of the logistic map is used to generate the chaotic signal and Pulse position modulation scheme together with the logistics map has been used to encrypt the signal.

TL;DR: In this article, the authors investigated whether it is possible to measure the coefficient of thermal expansion (CTE) of steel with the aid of the digital image correlation (DIC) technique.

TL;DR: In this article, the deformation heterogeneity in terms of the strain ex map obtained through the DIC method was characterized by a broadened band that was inclined at an angle of 75°.