Currently, laser module package is a popular product in optical fiber communication. In the laser module package process smallness is the key point, so dimensions control to influence the oscillation, ageing of material of the laser module operation. This study aim to simulate the laser module weld part's von Mises stress and the laser module weld part's von Mises strain (by using a commercial FEM package, ANSYS) in different temperature cyclic, From the finding of the study, different material property and geometry contour affect the laser module¡¦s ability and cyclic lifespan. For instance Thermal shock will influence the von Mises stress, and thermal cyclic influences viscoplastic strain range and use life. In addation, creep, ageing and stress relaxation happen easily in the high temperature. When the temperature fixes at cyclic period, changing dwell time affects more than changing ramp time. Furthermore, the effects of the study of solder¡¦s geometry contour and the solder¡¦s material property, the behavior of thermal, their advantage and their disadvantageously are also compared in this report. The future, the results obtained by the analytical model will refer to interrelated research.

The influence of different microstructural attributes on the material properties such strength, hardness, residual stress or other physical properties are very well understood. During the manufacturing of mechanical parts utilized in important industries such as energy, aerospace or biomedical, the effect of the processing in term of thermal and mechanical loading is very important as it is directly influencing the microstructure evolution and the properties. The understanding of how the manufacturing process such as high precision machining will affect first the microstructure and therefore the part properties. In this work, we propose the Materials-Affected Manufacturing (MAM). It is a new paradigm helping to understand the interaction between the manufacturing process parameters, materials microstructure attributes and the properties. This is solved using a computational approach using an iterative blending to relate different models. Residual stresses are also studied. An enhanced analytical model is proposed. The model is capable for the first time to predict analytically the residual stress regeneration in the multi-step machining problem. An enhancement of the existing model is proposed. The (MAM) method was applied to the case of turning process of Aluminum 7075. The average grain size and the crystallographic texture were predicted and validated experimentally. The residual stress regeneration was computed for the case of milling of Aluminum 2024. Experimental validations using X-ray technique were performed for validations.

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Dimensional stability of materials is of critical importance in the fabrication of precision components used for applications such as optical systems. One source of dimensional instability is residual stress produced on the surfaces of parts due to machining operations. A creep model is proposed in this research that describes how these stressed layers affect the overall geometry of a component as they creep over time and temperature. Depth corrected XRD stress measurements and a bimetallic strip model were utilized to quantify the residual stress layer of two machining operations. The creep model parameters were determined by monitoring curvature over time and temperature. This model can be used for two purposes, the prediction of long term storage effects on part geometry for purposes of reliability assessment, and the design of short term, moderate temperature stress relief treatments. Two alloys were investigated, aluminum 6061-T6, and aluminum 4032-0. A methodology for applying the observed creep strain to complex parts using a finite element analysis is proposed.

"Residual stresses are a common and often undesired result of material processing, introduced through non-linear deformation and/or phase transformation of material under mechanical or thermo-mechanical loading. These macro stresses alter mechanical properties and the intrinsic fatigue crack growth characteristics of the material. Residual stress artifacts can introduce inconsistencies and significant errors when the true material behavior is needed for material development and optimization and for structural component design. The effects of quenching residual stresses on fatigue crack propagation behavior of various materials were investigated. In parallel, residual stresses similar in magnitude and distribution with the quenching residual stresses were generated using mechanical processes to decouple the effects of residual stresses from microstructural effects. Mechanical residual stress distributions predicted by 3D elastic-plastic finite element analysis showed good agreement with the stresses measured on fatigue crack growth testing specimens using fracture mechanics approaches. Crack propagation characteristics in fields with low and high residual stresses were studied using optical and scanning electron microscopy, and the effects of residual stress on crack path behavior were assessed. An original residual stress analytical correction to fatigue crack growth data was developed, compared to existing corrective methodologies, and validated using residual stress free data. Overall, the work provides tools to understand, control, and correct the effects of processing residual stresses on fatigue crack growth for accurate fatigue critical design and life predictions."

Residual stresses are “locked-in” within a material, and exist without any external loads. Such stresses are developed during most common manufacturing processes, for example welding, cold working and grinding. These “hidden” stresses can be quite large, and can have profound effects on engineering properties, notably fatigue life and dimensional stability. To obtain reliable and accurate residual stress measurements for uniform and non-uniform stress states, a novel and practical method using crossing-slitting and ESPI is presented here. Cross-slitting releases all three in-plane stress components and leaves nearby deformation areas intact. The ESPI (Electronic Speckle Pattern Interferometry) technique gives an attractive tool for practical use, because measurements provide a large quantity of useful data, require little initial setup and can be completed rapidly and at low per-measurement cost. A new ESPI setup consisting of shutter and double-mirror device is designed to achieve dual-axis measurements to balance the measurement sensitivities of all in-plane stress components. To evaluate data quality, a pixel quality control and correction procedure is also applied. This helps to locate bad data pixels and provides opportunities to correct them. The measurement results show that this procedure plays an important role for the success of residual stress evaluation. Based on the observed displacement data and finite element calculated calibration data, an inverse computation method is developed to recover the residual stresses in a material for both uniform and non-uniform cases. By combining cross-slitting and ESPI, more reliable results for the three in-plane residual stress components can be obtained.

The goal of this research was to investigate an experimental infrared transmission technique and associated analysis tools that extract the in-plane residual stresses in thin single and poly-crystalline silicon sheet, and try to relate the residual stresses to physical parameters associated with silicon growth and cell processing. Previous research has suggested this concept, but many engineering and analytical details had not been addressed. In this research, a system has been designed and built. A fringe multiplier was incorporated into the system to increase the sensitivity. The error was analyzed and the resolution of the system was found to be 1.2~MPa. To convert the experimental results to residual stresses, the stress-optic coefficients of (001), (011) and (111) silicon were analyzed analytically and calibrated using a four-point bending fixture. Anisotropy in (001) and (011) silicon was found to be 33%, and the coefficient of EFG silicon is 1.7 times larger than that of (001) silicon. The polariscope together with other techniques was applied to silicon wafers after various processing steps in the manufacture of photovoltaic cells. The influence of the processing on residual stress was investigated and positive correlations between residual stresses, PL and efficiency were obtained.

The residual stress distribution, growth of Intermetallic Compound (IMC) layer and the equivalent strength in the Laser diode package are investigated in this thesis. The redistribution of residual stress in the solder layer is calculated by employing the MARC finite element package. The effects of residual stresses and IMC layer on the bonding strength of Laser diode under taken different thermal load cycles are studied. Numerical results are compared with the results measured experimentally. Results indicate the effect of residual stresses introduced in the solder solidification is so important in the stress analysis of a solder joint. The effects of different solder parameters, i.e, solder alloy, solder layer thickness and the number of thermal load cycles, are also analyzed in this work.. A better understanding about the solder bond strength is expected from this analysis.

Summary Residual stress dssess ment by means of the hole drilling techniqae is still regarded by many analysts as a phenomenon whose use is restricted to isotropic and homogeneous materials. The work caFried out in this paper tends to address this 'lack of certainty' through introdacing a verilication approach of experimentally assess ed residual stress values, The components investigated were produced under pure bending conditions and anulysed for their residual stress behaviour using a customized strain gaage rosette. This rosette was employed in order to detect the average and peak maximam strain relaxstion os a result of producing a hole by the high speed drilling technique. It is envisaged that the concept of the verffication method could lead to a better understanding with regard to residual stress analysis.