Thermo-Mechanical Analysis of a Laser Diode Chip in an Opto-Electronic Package

2009 ◽  
Author(s):  
Satish C. Chaparala ◽  
Lawrence C. Hughes ◽  
Jae Kwak ◽  
Seungbae Park
Keyword(s):  
Laser Diode ◽  
Failure Modes ◽  
Operating Conditions ◽  
Image Correlation ◽  
Fe Model ◽  
Substrate Thickness ◽  
Assembly Process ◽  
Package Design ◽  
The Impact ◽  
Dic Technique

It is a well-known fact that the lasers have wide variety of applications in diverse fields from medicine to communications [1]. Laser packaging involves appropriate materials selection and design to ensure that the laser performance meets the required specifications. In this paper, we present a GaAs based laser diode package design. The package design enables the laser diode chip to withstand the thermo-mechanical strains that are induced during the package assembly process as well as during the operating conditions. Excessive stresses in the chips could causes cracks in the chip. Excessive strains could cause un-desired spectral characteristics in the emitted light [2]. Therefore, the objective is to design a package that is tested and characterized to avoid these failure modes. This study presents numerical and experimental investigation of thermo-mechanical strains induced due to coefficient of thermal expansion (CTE) mismatch between various package components during assembly process. Finite element (FE) analysis is used to predict the displacements, tensile strains and stresses in the chip at various assembly processes. Digital Image Correlation (DIC) technique was used to measure the strains in the laser diode. Earlier, other researchers have used photo-luminescence methods and spectroscopic methods etc to measure packaging induced strains in the laser package [3]–[9]. The authors are not aware of any prior work where the DIC technique is applied on a very small chip for strain measurements Good correlation in displacements and strains was obtained between the model and the measurements, increasing confidence in the model. In addition, experiments were conducted to estimate the fracture strength of the GaAs to predict the chip failure based on the maximum principal stress criterion. The FE model was later used to conduct parametric study to analyze the impact of other factors on the chip stress such as substrate thickness, voids, thermal gradients in the package, surface irregularities in the chip etc. Experiments and model indicated that the designed package was robust enough and does not cause any damage to the chip.

scholarly journals Analysis for Shear Behavior of SRC Deep Beams Based on Tests, Digital Image Correlation Technique, and Finite Elemental Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Buqing Chen ◽  
Jun Wu ◽  
Changjun Liu ◽  
Yanhua Liu ◽  
Wenmei Zhou ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Failure Modes ◽  
Parameter Analysis ◽  
Image Correlation ◽  
Superposition Method ◽  
Deep Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Dic Technique

Seven steel-reinforced concrete (SRC) deep beams were tested to investigate the shear performance, including peak loads, failure modes, mid-span deflections, and cracking patterns. The parameters include the shear span-to-depth ratio and the dimensions of the steel skeleton. The digital image correlation (DIC) technique was utilized for real-time recording of the in-plane strain and deformation. The experiment results show that the failure modes of specimens could be concluded as two forms: diagonal compression failure and shear failure. The DIC technique was proved to be efficient for tracking the development of crack patterns and recording the failure modes. The corresponding numerical analyses based on experiments were carried out and demonstrated to be a reliable method to simulate the shear response. Furthermore, the most significant parameters and their interactions were identified by finite element models parameter analysis. The steel skeleton height and shear span-to-depth ratio were the main parameters affecting shear capacity. A design formula based on the strength superposition method was presented. The calculated results were basically in agreement with the test results, where the mean and coefficient of variation were 1.04 and 0.09, respectively.

Characterization of Mechanical Behavior of Polyurethane Foams Using Digital Image Correlation

2005 ◽  
Author(s):  
Helena (Huiqing) Jin ◽  
Wei-Yang Lu ◽  
Simon Scheffel ◽  
Michael K. Neilsen ◽  
Terry D. Hinnerichs
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Polyurethane Foams ◽  
Image Correlation ◽  
Compression Tests ◽  
Steel Cylinder ◽  
Full Field ◽  
Strain Concentration ◽  
The Impact ◽  
Dic Technique

Polyurethane foams have good energy absorption properties and are effective in protecting sensitive components from damages due to impact. The foam absorbs impact energy by crushing cells and undergoing large deformation. The complex deformation of the foam needs to be modeled accurately to simulate the impact events. In this paper, the Digital Image Correlation (DIC) technique was implemented to obtain the deformation field of foam specimens under compression tests. Images of foam specimen were continuously acquired using high-speed cameras. The full field displacement and strain at each incremental step of loading were calculated from these images. The closed-cell polyurethane foam used in this investigation was nominal 0.32 kg/m^3 (20 pcf). In the first experiment, cubic specimens were compressed uniaxially up to 60%. The full-field displacements and strains obtained using the DIC technique provide detailed information about the inhomogeneous deformation over the area of interest during loading. In the second experiment, compression tests were conducted for a simple foam structure - cubic foam specimens with a steel cylinder inclusion. The strain concentration at the interface between steel cylinder and foam was studied to simulate the deformation of foam in a typical application. In the third experiment, the foam was loaded from the steel cylinder during the compression. The strain concentration at the interface and the displacement distribution over the surface were compared for cases with and without a confinement fixture to study the effects of confinement. These experimental results demonstrate that the DIC technique can be applied to polyurethane foams to study the heterogeneous deformation. The experimental data is briefly compared with the results from modeling and simulation using a viscoplastic model for the foam.

Failure analysis and fatigue life prediction of high-speed rail clips based on DIC technique

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110662
Author(s):  
Yan Liu ◽  
Xiujie Jiang ◽  
Qiutong Li ◽  
Huan Liu
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Fatigue Failure ◽  
High Speed ◽  
Experimental Tests ◽  
Image Correlation ◽  
Fe Model ◽  
Rail Transportation ◽  
High Speed Rail ◽  
Dic Technique

With the development of rail transportation, the fatigue failure of rail clips has become an issue, which affects the operational safety of trains. In this study, reasons for the fatigue failure of rail clips were investigated to improve their service life. A digital image correlation (DIC) technique was conducted to obtain strain fields, vibration modes, and natural frequencies of a rail clip. The strain and displacement of a rail clip under dynamic cyclic loading were also obtained. A fastener system refinement model was developed to analyze the static, dynamic, and modal responses of the clip. The experimental tests and modal simulation results were mutually verified. The fatigue life was analyzed based on the verified FE model. The results revealed that the maximum strain and minimum fatigue life occur at the heel of the clip, in good agreement with the actual fracture position. As the amplitude and frequency of dynamic cyclic load increased, the fatigue life of the clip decreased sharply. Moreover, the normal wheel–rail force accompanied by high-frequency rail corrugations accelerated crack initiation and reduced the fatigue life. The findings of this study provide guidance for improving the service life of rail clips.

scholarly journals A Study of Multi-Objective Crashworthiness Optimization of the Thin-Walled Composite Tube under Axial Load

Vehicles ◽  
2020 ◽  
Vol 2 (3) ◽  
pp. 438-452
Author(s):  
Mohammad Reza Seyedi ◽  
Abolfazl Khalkhali
Keyword(s):  
Failure Mechanism ◽  
Energy Absorption ◽  
Failure Modes ◽  
Matrix Material ◽  
Load Condition ◽  
Fe Model ◽  
Absorption Mechanism ◽  
Multi Objective ◽  
Thin Walled ◽  
The Impact

In recent decades, thin-walled composite components have been widely used in the automotive industry due to their high specific energy absorption. A large number of experimental and numerical studies have been conducted to characterize the energy absorption mechanism and failure criteria for different composite tubes. Their results indicate that the energy absorption characteristics depend highly on the failure modes that occur during the impact. And failure mechanism is dependent on fiber material, matrix material, fiber angle, the layout of the fibers, as well as the geometry of structure and load condition. In this paper, first, the finite element (FE) model of the CFRP tube was developed using the Tsai-Wu failure criterion to model the crush characteristics. The FE results were validated using the published experimental. Then, a series of FE simulations were conducted considering different fiber directions and the number of layers to generate enough data for constructing the GMDH-type neural network. The polynomial expression of the three outputs (energy absorption, maximum force, and critical buckling force) was extracted using the GMDH algorithm and was used to perform the Pareto-based multi-objective optimizations. Finally, the failure mechanism of the optimum design point was simulated in LS-DYNA. The main contribution of this study was to successfully model the CFRP tube and damage mechanism using appropriate material constitutive model’s parameters and present the multi-objective method to find the optimum crashworthy design of the CFRP tube.

scholarly journals The Use of Reliability Based Limit State Methods in Uprating High Pressure Pipelines

1998 ◽  
Author(s):  
Andrew Francis ◽  
Richard Espiner ◽  
Alan Edwards ◽  
Gary Senior
Keyword(s):  
Failure Probability ◽  
Probabilistic Analysis ◽  
Failure Modes ◽  
Limit State ◽  
Operating Conditions ◽  
Operating Pressure ◽  
New Materials ◽  
Limit State Design ◽  
The Impact ◽  
Transmission Pipelines

There is an increasing demand for operators of transmission pipelines to maximise the throughput of their pipeline systems. This can be achieved relatively easily with new pipelines, by using limit state design, new materials, novel fabrication techniques etc., Operators are also looking to maximise the throughput of existing transmission pipelines. Obviously, they are not able to make use of new materials etc., but limit state design concepts can be applied to show that a pipeline can be safely uprated to a higher design pressure. The limit state of an engineering structure or component is defined as the mathematical relationship between the parameters associated with a particular failure mode at the onset of failure. To assess the impact on pipeline integrity and safety, a limit state approach incorporating probabilistic analysis has been developed. The approach addresses all credible failure modes and takes account of uncertainties in the relevant parameters for each mode. The probabilistic approach takes the limit state approach a step further by describing the parameters as statistical distributions rather than single values. This allows failure probabilities to be computed which are a more meaningful measure of safety and allow areas of over conservatism (or under conservatism) to be identified. It is important to note that the approach is only as good as the limit states used and the data used to construct the distributions. Clearly uncertainties in both of these can exist and the absolute values of the computed probabilities must be viewed with caution. However, the strength of the approach lies in the relative values of the computed probabilities and previous ‘safe’ operation. If a system has a significant operational history with few or no failures and it can be shown that there is little change in the theoretical failure probability associated with a change in operating conditions, it can be inferred that few or no failures will occur in practice. The paper describes the above approach in detail and outlines a study carried out to determine the effect on pipeline integrity of uprating three pipelines from a current maximum operating pressure of 70 bar to an uprated pressure of 85 bar, exceeding the current design criteria. By application of the limit state approach incorporating probabilistic analysis, it is shown that there would be an insignificant change in failure probability as a result of uprating to 85 bar, and hence that the integrity of the pipelines is unimpaired by uprating.

scholarly journals Mechanical characterization and numerical modeling of TPMS lattice structures subjected to impact loading

2021 ◽  
Vol 250 ◽  
pp. 02005
Author(s):  
Rafael Santiago ◽  
Sarah Almahri ◽  
Dong-Wook Lee ◽  
Haleimah Alabdouli ◽  
Omar Banabila ◽  
...  
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
High Energy ◽  
Image Correlation ◽  
Dynamic Strain ◽  
Correlation Technique ◽  
Fe Model ◽  
Strain Rates ◽  
The Impact ◽  
Constitutive Parameters

The advent of Powder Bed Fusion (PBF) techniques allows the additive manufacturing of complex structures, as Triply Periodic Minimal Surfaces (TPMS) lattices, which exhibit promising characteristics for impact applications, such as lightweight and high-energy absorption. Thus, this work aims to develop a numerical model of TPMS structures to investigate the mechanical response of such structures when subjected to impact loadings. To fulfill this task, stainless steel samples made by PBF technique were mechanically characterized at different strain rates using a universal testing machine and Split Hopkinson Pressure Bar. The testing campaign also explored the compressive and tensile material response, with the strain field being monitored by Digital Image Correlation technique. It was noted that the material exhibits a similar elasto-plastic response on both tension and compression and an evident strain rate hardening when the material is loaded from static (0.001 s-1) to dynamic strain rates (4000 s-1). Constitutive parameters were then obtained and implemented in an explicit finite element model developed through Abaqus CAE. Samples of TMPS lattices were manufactured and tested at different loading velocities, which showed that the FE model developed can be used to predict the impact response of TMPS lattices.

scholarly journals Explicit Simulation of Circular CFST Stub Columns with External Steel Confinement under Axial Compression

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 23 ◽  
Author(s):  
Faesal Alatshan ◽  
Siti Aminah Osman ◽  
Fidelis Mashiri ◽  
Roszilah Hamid
Keyword(s):  
Failure Modes ◽  
Axial Loading ◽  
Steel Tube ◽  
Fe Model ◽  
Explicit Finite Element ◽  
Steel Ratio ◽  
Short Columns ◽  
Early Loading ◽  
Experimental Findings ◽  
The Impact

Concrete-filled steel tube (CFST) structural members have been widely used in engineering projects for their superior strength and ductility. However, the different lateral dilation characteristics between concrete infill and steel tube have caused imperfect composite interaction during the early loading stage. To overcome this issue, external steel confinements in the form of rings and spiral were previously suggested to minimise the lateral expansion of the steel tube and enhance the concrete confinement effects. This study presented the analytical behaviour of circular CFST short columns with an external ring or spiral confinements which are subjected to axial loading. An explicit finite element (FE) model was developed and verified based on previous experimental findings. Besides that, this study analysed the failure modes, axial load–strain relationship, stress distributions, and bond strength of the composite column components. Parametric analysis was also undertaken to evaluate the impact of material strengths, total steel ratio, and diameter-to-thickness ratio. The results suggest that the use of external steel confinement can enhance the compressive behaviour of CFSTs better than increasing the thickness of the steel tube when using the same steel ratio. Finally, simplified design formulations were developed to accurately calculate the ultimate capacity of CFST columns with and without external steel confinement.

Static and Localized Strain Analysis of High Hardened Linear Model Mock-Up Bearing for Fast Breeder Reactor

2015 ◽  
Vol 830-831 ◽  
pp. 223-226 ◽  
Author(s):  
S. Babu ◽  
K. Manisekar
Keyword(s):  
Linear Model ◽  
Large Diameter ◽  
Strain Analysis ◽  
Image Correlation ◽  
Strain Sensitivity ◽  
Fast Breeder Reactor ◽  
Set Up ◽  
Steel Balls ◽  
The Impact ◽  
Dic Technique

This paper investigates the impact of strain sensitivity on the linear model mock-up bearing (LMMB) using digital image correlation (DIC) technique. This work addresses the lack of norms, standards, reference of elastic/plastic deformation of bearings elements. Towards that, experimental set-up was designed and fabricated with a set of LMMB (AISI4140) with commercially purchased steel balls (AISI52100) to study the raceway relative approach and localized strain rate on steel ball, wherein raceway relative approach is measured using LVDT & screw gauge and results are compared with DIC results. These data are very much useful in design and development of large diameter slewing bearing for fast breeder reactor and also these results can be used to optimize the number of ball, load, and tolerance on bearing.

scholarly journals An Experimental Study in the Hydroelastic Response of an Aluminum Wedge in Drop Tests

2017 ◽  
Author(s):  
Jonathan R. Eastridge ◽  
Brandon M. Taravella
Keyword(s):  
Impact Velocity ◽  
High Speed ◽  
Operating Conditions ◽  
Image Correlation ◽  
Elastic Response ◽  
Future Research ◽  
Strain Gages ◽  
Drop Tests ◽  
Hydroelastic Response ◽  
Dic Technique

Slamming of high speed marine planing craft is an important part of their operating conditions. High hydrodynamic forces are inevitably induced causing the shell plating to deflect, which in turn can influence the flow physics surrounding the hull. In order to study the hull’s hydroelastic behavior due to a slamming event, the researchers performed wedge drop experiments with an aluminum wedge of 57 inches in length, 47 inches in breadth, and 20∘ deadrise with 1/4 inch thick unstiffened bottom panels. The elastic response of the bottom plating was measured via two methods. The first method uses a series of evenly-space, colinear strain gages, and the second method is a stereoscopic digital image correlation (S-DIC) technique. In this investigation, an S-DIC code has been developed and utilized to study the deflections and to advance the capabilities of future research. Drops have been made for four impact velocities: 4.8 ft/s, 6.8 ft/s, 8.4 ft/s, and 9.7 ft/s. Comparisons are made between the two methods at an impact velocity of 9.7 ft/s – only strain gages were used for the lesser impact velocities. The overall deflections of the deadrise panel are approximately 1/10 inch at an impact velocity of 9.7 ft/s. The predictions made using S-DIC and strain gages differ by approximately 23%.

Experimental Study on Masonry Panels Strengthened by GFRP: The Role of Inclination between Mortar Joints and GFRP Sheets

2014 ◽  
Vol 624 ◽  
pp. 559-566 ◽  
Author(s):  
Claudio Mazzotti ◽  
Barbara Ferracuti ◽  
Alessandro Bellini
Keyword(s):  
Failure Modes ◽  
Vertical Axis ◽  
Image Correlation ◽  
Masonry Walls ◽  
Shear Tests ◽  
Shear Strengthening ◽  
Lap Shear ◽  
Dic Technique ◽  
Frp Sheet

For the shear strengthening of masonry walls, different configurations for FRP sheets are currently used in real application, such as vertical, horizontal or diagonal strips. In the last configuration the FRP sheet is inclined with respect to the direction of mortar joints. In the experimental campaign presented in this paper, it is investigated whether the FRP-masonry bond could be affected by this inclination. In order to analyze this issue, three different typologies of masonry panels (with different textures) retrofitted by FRP sheets, inclined of 45 degrees with respect to the vertical axis of the specimen, are subjected to single-lap shear tests. Results of shear tests are presented in terms of maximum debonding forces, force-elongation curves, failure modes and strain profiles along the specimens. The use of Digital Image Correlation (DIC) technique allowed to obtain complete strain maps on the surface of the specimens tested, with the purpose of investigating possible variations in the strain field within the bonded area.

Sign in / Sign up

Export Citation Format

Share Document