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Articles 1 - 13 of 13
Full-Text Articles in Mechanical Engineering
Study Of Selective Laser Remelting Of 316l S.S. To Reduce Roughness On Inclined Surface, Jafar Ghorbani
Study Of Selective Laser Remelting Of 316l S.S. To Reduce Roughness On Inclined Surface, Jafar Ghorbani
Theses and Dissertations
Additive manufacturing (AM) technologies are increasingly competing with subtractive methods, and there are promising applications for additive technologies that are hybrid with traditional manufacturing methods. Poor surface roughness of additive manufactured parts continues to be a major challenge especially for advanced functional parts. In this study, effect of processing parameters are evaluated, optimized and verified by using the Box–Behnken design of experiment method. The results, for the first time, reveal that surface remelting has the potential to become a high speed approach for improving the roughness of non-horizontal surface of additive manufactured parts.
The Effect Of Process Parameters And Surface Condition On Bond Strength Between Additively Manufactured Components And Polymer Substrates, Bharat Bhushan Chivukula
The Effect Of Process Parameters And Surface Condition On Bond Strength Between Additively Manufactured Components And Polymer Substrates, Bharat Bhushan Chivukula
Graduate Theses and Dissertations
Additive patching is a process in which printers with multiple axes deposit molten material onto a pre-defined surface to form a bond. Studying the effect of surface roughness and process parameters selected for printing auxiliary part on the bond helps in improving the strength of the final component. Particularly, the influence of surface roughness, as established by adhesion theory, has not been evaluated in the framework of additive manufacturing (AM). A full factorial design of experiments with five replications was conducted on two levels and three factors, viz., layer thickness, surface roughness, and raster angle to examine the underlying effects …
Novel Closed-Loop Control Strategy For Inkjet-Based Additive Manufacturing System, Yunong Shi, Chunsheng Ye
Novel Closed-Loop Control Strategy For Inkjet-Based Additive Manufacturing System, Yunong Shi, Chunsheng Ye
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Calphad-Based Materials Genome And Its Applications To Additive Manufacturing, Wei Xiong
Calphad-Based Materials Genome And Its Applications To Additive Manufacturing, Wei Xiong
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
A Smooth Toolpath Generation Method For Laser Metal Deposition, Renwei Liu, Zhiyuan Wang, Yunlu Zhang, Todd E. Sparks, Frank W. Liou
A Smooth Toolpath Generation Method For Laser Metal Deposition, Renwei Liu, Zhiyuan Wang, Yunlu Zhang, Todd E. Sparks, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Laser metal deposition (LMD), also known as direct metal deposition (DMD) or laser engineered net shaping (LENS), which uses a laser beam to form a melt pool on a metallic substrate, into which powder or wire is fed. The conventional contour and zigzag toolpath pattern for LMD are discontinuous at turn points or corner points. The discontinuous toolpath causes uneven deposition, which brings height variation and porosity problems. This paper aims to develop a smooth toolpath generation method for LMD to improve the deposition quality. A parametric curve equation based on trigonometric functions is derived and built. It can be …
Applications Of Additive Manufacturing Techniques In Making Energetic Materials, Peter A. Cattani, Trevor J. Fleck, Jeff F. Rhoads, Steven F. Son, I. Emre Gunduz
Applications Of Additive Manufacturing Techniques In Making Energetic Materials, Peter A. Cattani, Trevor J. Fleck, Jeff F. Rhoads, Steven F. Son, I. Emre Gunduz
The Summer Undergraduate Research Fellowship (SURF) Symposium
Energetic materials are currently manufactured using methods such as casting, which can only produce certain geometries. Additive manufacturing enables more flexible fabrication and the potential for improved material consistency. Additive manufacturing has transformed many industries, but has only recently been applied to the manufacturing of energetic materials. This paper describes the development of two processes to apply additive manufacturing methods to energetic materials. Method one applies a fused deposition modelling approach (FDM). 5 µm aluminum powder and PVDF were mixed and made into filaments using a Filabot Original filament extruder. Energetic filaments were created composed of 90:10, 80:20, and 75:25 …
Development Of The Compact Jet Engine Simulator From Concept To Useful Test Rig, Henry H. Haskin
Development Of The Compact Jet Engine Simulator From Concept To Useful Test Rig, Henry H. Haskin
Mechanical & Aerospace Engineering Theses & Dissertations
Two Compact Jet Engine Simulator (CJES) units were designed for integrated wind tunnel acoustic experiments involving a Hybrid Wing Body (HWB) vehicle. To meet the 5.8% scale of the HWB model, Ultra Compact Combustor technology from the Air Force Research Laboratory was used. The CJES units were built and integrated with a control system in the NASA Langley Low Speed Aero acoustic Wind Tunnel. The combustor liners, plug—vane and flow conditioner components were built in-house at Langley Research Center. The operation of the CJES units was mapped and fixes found for combustor instability tones and rig flow noise. The original …
Effects Of Defects On The Performance Of Hierarchical Honeycomb Metamaterials Realized Through Additive Manufacturing, Kazi Moshiur Rahman
Effects Of Defects On The Performance Of Hierarchical Honeycomb Metamaterials Realized Through Additive Manufacturing, Kazi Moshiur Rahman
Electronic Theses and Dissertations
Cellular metamaterials are of immense interest for many current engineering applications. Tailoring the structural organization of cellular structures leads to new metamaterials with superior properties providing lightweight and very strong/stiff structures. The incorporation of hierarchy to regular cellular structures enhances the properties and introduces novel tailorable metamaterials. For many complex cellular metamaterials, the only realistic manufacturing process is additive manufacturing (AM). The use of AM to manufacture large structures may lead to several types of defects during the manufacturing process, such as imperfect cell walls, irregular thickness, flawed joints, partially missing layers, and irregular elastic plastic behavior due to toolpath. …
Manufacturing And Mechanics Of Polymer Matrix Composites, Md Shariful Islam
Manufacturing And Mechanics Of Polymer Matrix Composites, Md Shariful Islam
Open Access Theses & Dissertations
Fiber-reinforced composite materials are widely used in the aerospace and automobile industries. Their strength-to-weight and stiffness-to-weight ratios make them suitable to be used in spacecraft, especially as cryogenic tank materials. One of the focus of this dissertation is to investigate the application of woven carbon and Kevlar® fiber composites as cryogenic tank materials. Tensile, bending and short beam shear tests are performed on rectangular specimens at room temperature and after cryogenic exposure (-196°C). It is found that the mechanical properties of these composite materials do not degrade significantly due to cryogenic exposure. It is observed that the failure mode took …
Effect Of Sparse-Build Internal Structure On Performance Of Fused Deposition Modeling Parts, Shixuan Meng
Effect Of Sparse-Build Internal Structure On Performance Of Fused Deposition Modeling Parts, Shixuan Meng
Masters Theses
"Fused deposition modeling (FDM) technology has been used in additive manufacturing for years and is able to significantly reduce both manufacturing time and cost for production tooling and end-use parts. Autoclave molding is one of the conventional tools used to produce composite parts. In autoclave molding, the soft composite material is positioned on the molding tool, and then subjected to vacuum and elevated temperatures to facilitate the curing of the resin. With additive manufacturing (AM), it is possible to fabricate the molding tool with a sparse internal structure, thereby reducing the fabrication time and cost compared to a solid tool. …
Thermophysical And Thermochemical Property Measurement And Prediction Of Liquid Metal Titanium Alloys With Applications In Additive Manufacturing, Jonathan Richard Raush
Thermophysical And Thermochemical Property Measurement And Prediction Of Liquid Metal Titanium Alloys With Applications In Additive Manufacturing, Jonathan Richard Raush
LSU Doctoral Dissertations
Accurate high-temperature thermophysical property data for liquid metals and alloys are important for simulation of laser-based 3D printing processes. To understand and better control such additive manufacturing processes, knowledge of density, viscosity, and surface tension of liquid metals and alloys versus composition and temperature is needed. Likewise, thermochemical property data information regarding alloys, including chemical activities and free energies relative to composition and temperature, aid in the understanding and development of phase data important in the material design process. Vacuum electrostatic levitation (ESL) is an important technique through which both thermophysical and thermochemical property measurements can be accomplished without physical …
Design Optimization Of Sandwich Core, Mohammad Tauhiduzzaman
Design Optimization Of Sandwich Core, Mohammad Tauhiduzzaman
Open Access Theses & Dissertations
Ultralight sandwich structures comprising of low-density core with stiff facings have attracted significant research interest for their considerable weight saving applications. The aircraft industries are focusing on decreasing the structural mass to lower the manufacturing and operating costs. Design analysis of the sandwich cores using finite element analysis has been developed as a promising concept to feature sandwich structures with maximum strength, stiffness, and reduced weight. To obtain multifunctional behavior of sandwich panels, a profound investigation of geometrical and mechanical properties in the transverse plane is required because it is very susceptible to any kind loadings. Structural optimization is one …
Hierarchical Control Of Complex Manufacturing Processes, Hesam Zomorodi Moghadam
Hierarchical Control Of Complex Manufacturing Processes, Hesam Zomorodi Moghadam
Doctoral Dissertations
"The need for changing the control objective during the process has been reported in many systems in manufacturing, robotics, etc. However, not many works have been devoted to systematically investigating the proper strategies for these types of problems. In this dissertation, two approaches to such problems have been suggested for fast varying systems. The first approach, addresses problems where some of the objectives are statically related to the states of the systems. Hierarchical Optimal Control was proposed to simplify the nonlinearity caused by adding the statically related objectives into control problem. The proposed method was implemented for contour-position control of …