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 50 for “"Dimensional accuracy"”.
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Dimensional Accuracy of Thermoset Polymer Composites: Process Simulation and Optimization
Finally, the three-dimensional finite element code is utilized to predict the viscoelastic response of a woven composite substrate for multilayer circuit board applications. Comparisons between numerical predictions and experimental data clearly indicate that the creep compliance of the composite …
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Development of a layerless additive manufacturing stereolithography machine to improve surface quality and dimensional accuracy
… the optimal parameters in order to obtain a more dimensionally accurate and higher surface quality part. A variety of geometric features are constructed through experiments and their properties are examined to extract the most adequate fabrication parameters. The layerless process was found to …
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Evaluating Dimensional Accuracy and Reliability of "Stitched" Small Field of View (SSFOV) Cone Beam Computed Tomography (CBCT) Datasets for Use in Proprietary Dental Implant Guided Surgery Software
… treatment and superior planning ability and accuracy for the clinician.</p> <p><strong>Objective: </strong>The purpose of this study was to evaluate the dimensional accuracy and reliability of stitched SFOV CBCT reconstructed images for use in the fabrication of surgical dental implant …
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Modeling, Parameter Estimation and Compensation of Quasistatic Errors in Multi-Axis CNC Machining Centers
Dimensional accuracy is often the single most critical criterion that can be used to evaluate the quality of machined parts. Increasing demand for highly accurate and inexpensive mechanical parts has created a critical need for developing economical and efficient processes for their production.
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Mechanical properties of rapid manufacturing and plastic injection molding
… methods. This paper compares the results of dimensional accuracy, tensile strength, elongation and elongation at break, shore hardness, and water absorption of an ASTM D638 Type IV test specimen created using plastic injection molding and rapid prototyping. The plastic injection molded parts …
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Optimization of modular die design in extrusion process
… of the extruding product. Surface finish and dimensional accuracy are the two most important criteria that specify the productivity and feasibility of the extrusion process which is highly influenced by the flow of aluminum through the deforming die. Therefore, die design is considered as one …
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Curved brick design methodology and manufacturing system
… accurately than existing bricks. The increase in dimensional accuracy is able to dramatically reduce the cost of construction in developing areas. A design is then offered for a low-cost press for these brick geometries that can be produced by local fabricators in developing areas.
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A comparative study of rapid prototyping systems
… aims to provide general information including dimensional accuracy and tensile properties for different build orientations, and relative water absorption and Shore hardness properties between different Rapid Prototyping systems. Test specimens were fabricated in four popular commercial Rapid …
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Development of P-3DP (Powder-based 3D Printing) technologies for the production of cement-based materials
… key processing variables have on structural and dimensional performance variation of the printed components. Binder jetting has the potential for complex geometries with high precision, along with minimum material waste, which is yet to be transformed into consistent mechanical strength and …
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Alloy design or three-dimensional printing of hardenable tool materials
Three-dimensional printing (3DP) is a state-of-the-art manufacturing technology, One of its many important applications is to fabricate the metal tooling for plastic injection molding. In order to achieve a fully dense 3DP metal tool, the current 3DP process involves five steps: printing, …
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Accurate nanofabrication techniques for high-index-contrast microphotonic devices
… microphotonic devices: sidewall roughness and dimensional accuracy. The work focuses on fabrication of optical add-drop filters based on high-index contrast microring-resonators. The fabrication is based on direct-write scanning-electronbeam lithography. A sidewall-roughness characterization …
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Simultaneous Localization and Calibration in a Wireless Network of Uncooperative Nodes
… protocol supports indoor localization with 1-2 m accuracy by allowing two devices to cooperatively measure their signal round-trip-time (RTT). But as of 2023, few commercially-deployed Wi-Fi access points (APs) actually support the protocol. Using a one-sided RTT measurement technique that does …
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High green density metal parts by vibrational compaction of dry powder in three dimensional printing process
The material properties and dimensional accuracy of metal tooling produced by the Three Dimensional Printing process can be enhanced by increasing the green density of the 3D printed part. Green density is the ratio of metal powder volume to the external volume of the printed part, and is a measure …
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An environmental impact analysis of grinding
… parts with a fine surface finish and high dimensional accuracy and for shaping hard or brittle workpieces. There are a wide variety of different types of grinding machines, each with different applications and slightly different energy requirements. Workpieces are generally flooded with a …
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Characterization of the Surface Roughness of Overhangs manufactured by Laser Powder Bed Fusion Process using Design of Experiments
… outputs connected to the melt pool, density, dimensional accuracy, and surface roughness of the coupons printed. Optimal parameter ranges can then be determined according to different design and process priorities. The framework developed in this project enables a material and machine agnostic …
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Improving Ink Feedback Control System for Vision Controlled Jetting 3D Printer
… require high precision. However, to maintain its dimensional accuracy while printing in a noisy environment, it requires the usage of a noise-robust ink controller algorithm to generate an appropriate printing layer based on the scanning information. The current VCJ controller algorithm, not able …
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Laser Powder Bed Fusion Process Characterization: Design of Experiments for Dimensionally Accurate Thin Walls
… outputs connected to the melt pool, density, dimensional accuracy, and surface roughness of the coupons printed. Optimal parameter ranges can then be determined according to different design and process priorities. The framework developed in this project enables a material and machine agnostic …
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Exploration of metal 3-D printing technologies for the microfabrication of freeform, finely featured, mesoscaled structures
… 3-D printing methods includes the assessment of dimensional accuracy and in-plane minimum feature size, measurement of vacuum outgassing and porosity, and estimation of thermal and electrical properties of the printed parts. The data demonstrate that binder inkjet printing of SS 316L has …
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Framework to Accelerate Parameter Development for Laser Powder Bed Fusion
… outputs connected to the melt pool, density, dimensional accuracy, and surface roughness of the coupons printed. Optimal parameter ranges can then be determined according to different design and process priorities. The framework developed in this project enables a material and machine agnostic …
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