Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 26 for “"warpage"”.
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Bending and warpage of elastic plates
This thesis presents two studies on elastic plates. In the first study, we discuss the choice of elastic energies for thin plates and shells, an unsettled issue with consequences for much recent modeling of soft matter. Through consideration of simple deformations of a thin body in the plane, we …
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Investigating Moisture Gradient-Induced Warpage of Veneers
… process. Out-of-plane deformation, or warpage, of wood veneers caused by changes in moisture content affects the ability to press flat panels. To understand wood panel warpage, experimental methods are developed to create and measure moisture-induced deformation of wood veneers on five …
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Numerical Modeling Analysis of Wafer Warpage and Carrier Mobility Change due to Tapered Through-Silicon-Via Geometry
… issue is that tapered TSV can cause wafer warpage during the fabrication processes. Wafer warpage can cause chip misalignment and impose additional deformation. In an effort to investigate the TSV geometric effect, a large number of finite element analysis (FEA) simulations were performed …
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Modeling of the in-Plane Biaxial Residual Stresses From Machining
… of machining-induced residual stress on part warpage. The experimentation indicates the strong influence of machining-induced residual stresses on component geometry. Finite element solution techniques are utilized to predict the part warpage resulting from the machining-induced residual …
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Dimensional Stability of Multilayer Circuit Boards
… are performed to study residual deformation and warpage in a model multilayer circuit board construction of a common composite substrate (7628 fabric style). A numerical procedure based on classical lamination theory with non-isothermal viscoelastic constitutive relations is developed to predict …
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Design of experiment analysis of an electronics package lid using finite element analysis
… of experiment analysis is reported on data from warpage simulations using finite element analysis of a lidded electronics package. Warpage in a lid of an optical electronics package can detrimentally affect the reliability of the package as well as its optical performance. The present study …
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The effect of injection molding processing conditions and fiber content towards the properties of polypropylene-nanoclay nanocomposites blend with gigantochloa scortechinii fibers
… the data of flexural strength, shrinkage and warpage, the measurement process and flexural strength tests were done. As a result, the minimum value of warpage was 0.003 mm, shrinkage of 0.00048 mm and maximum flexural strength was 36.3390 MPa. To get the best results for flexural strength, the …
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Defect Detection in Selective Laser Melting
… to print a test coupon with inherent defects – warpage and cracking. Data recorded during the build was then characterized to determine when the defects occurred.</p> <p>The test coupon was printed using two sets of print parameters developed to control the severity of warpage and cracking. The …
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Dimensional Stability and Properties of Thermoplastics Reinforced with Particulate and Fiber Fillers
… concerned with ascertaining the main causes of warpage observed for injection-molded thermoplastics reinforced with high aspect ratio fibers. Typically, warpage in injection-molded fiber reinforced thermoplastics is primarily attributed to residual thermal stresses associated with shrinkage and …
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Investigation of Residual Stresses in Shape Memory Alloy (Sma) Composites
… wires embedded in a host matrix. A series of warpage experiments were conducted on nitinol composite beams during heating cycles to provide experimental validation of model predictions and to assess their thermoelastic structural behavior under non-mechanical loading. Micromechanical model …
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Modeling and control of rapid cure in polydimethylsiloxane (PDMS) for microfluidic device applications
… and is important for modeling shrinkage and warpage. A novel heated microindentation setup is designed to monitor curing of thin PDMS films, and experimentally validate the theory. The second part of this thesis presents a model for final PDMS shrinkage and warpage using the gel point. …
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Heat Treatment of Orthodontic Steel Wire
… wire; c) the effect of heat treatment on the warpage of a orthodontic wire which has previously been formed. A standardized nine millimeter vertical loop was incorporated in the wire. Weights in increments of 100 grams were suspended from one end of the wire while the other end was firmly held …
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The modelling of processing conditions for polypropylene-nanoclay integral hinges at high heat exposure
… for ultimate tensile strength, shrinkage and warpage. This research had adopted Taguchi Optimisation Method, to optimise the processing conditions, to generate the regression models and to construct master curves for quality performance prediction based on nanoclay content. According to the …
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Thermo-mechanical Analysis of a Custom PCB-DBC Hybrid Package for a (650 V, 150 A) e-GaN HEMT
… fracture of bonds caused by thermally induced warpage. The thermal warpage is the consequence of the bonded package components having a coefficient of expansion (CTE) mismatch while being subjected to temperature changes during operation. Multiphysics simulation software have previously …
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Analysis of sintered WC-TIC-6CO by using powder metallurgy process
… the best combination parameter for minimizing warpage, shrinkage, and density value were obtained with a result of 0.0124 mm of warpage, shrinkage value improved by 33.34%, while for density, it can be inferred as improving about 1.63% which increased from 5.3968 g/cm3 to 5.48486 g/cm3. For the …
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Evaluation on performance of square finned conformal cooling channel (sfccc) fabricated by selective laser melting (slm) on plastic moulded part
… shrinkage in relation to the shrinkage and warpage at points X and Y direction. Most front panel housing shrinkage and warpage values in the experimental study were smaller than those of the simulative study. However, the experimental results were in line with the simulative results, proving …
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Deformations of Unsymmetric Composite Panels
… and mechanical loads. Chapter 2 focuses on the warpage of large unsymmetric curved composite panels due manufacturing anomalies. These panels are subjected to a temperature change of -280°F to simulate the cooling from the autoclave cure temperature. Sixteen layer quasi-isotropic, axial-stiff, …
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Integration of Power Electronics Building Block Using Polyimide Substrates
… effects of thick copper layers and large-area warpage. Experimental thermal cycling and warpage measurements are conducted to validate the mechanical reliability. These findings help inform limitations of polyimide substrates and highlight tradeoffs for use in high-power applications. To …
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Characterization of Flexible Hybrid Electronics Using Stretchable Silver Ink and Ultra-Thin Silicon Die
… was shown between die thickness and die warpage, likely due to high levels of internal stress caused by the dicing and thinning process. Finally, an innovate pairing of serpentine copper clad traces on TPU was tested for reliability performance using traditional solder for die …
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Additive Manufacturing of Commercial Polypropylene Grades of Similar Molecular Weight and Molecular Weight Distribution
… with improved interlayer adhesion and reduced warpage in printed structures. However, this improvement is accompanied by a tradeoff, resulting in inferior tensile strength and an increased degree of print orientation anisotropy.
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