Non-uniform mesh for embroidered microstrip antennas

This paper presents a non-uniform meshed embroidered structure for wearable microstrip patch antennas. The non -uniform meshed patch antenna (NMPA) has significantly less conductor coverage than a conventional patch antenna without significantly compromise the antenna performance. For wearable applications, less conductor coverage reduces the usage of the specialised conductive materials which are currently expensive. The embroidered NMPA reduced manufacturing cost and improves the flexibility. In this paper, the surface current distribution and the effect of the meshing size of NMPAs have been simulated and analysed. Fully textile embroidered NMPA on felt substrate has been fabricated and measured. Representative results showed the NMPA had a 60% total antenna efficiency with 20% conductor area coverage

Modeling and testing of stitched composite laminates for enhanced interlaminar strength

This research assesses the effects of stitching a four-layer E-glass/Epoxy cross-ply laminate with translaminar reinforcement consisting of E-glass yarns. Both experimental characterization and finite element analysis have been employed to accurately predict and analyze the properties of the stitched material.;Tensile and Double Cantilever Beam testing indicated that translaminar stitching degrades the effective extensional modulus of the laminate by about 15.9 percent, while it enhances the opening Mode I interlaminar fracture toughness. This degradation in the effective in-plane stiffness is attributed to the localized damage inflicted on the fiber plies by the needle penetration of the sewing machine used to insert the transversely reinforcing stitch.;The finite element model predicted a more rigid effective extensional modulus of 2.44 MSI, which is approximately 2.9 percent higher than the corresponding experimental value of 2.37 MSI. This difference can be attributed to slippage effects along the fiber-matrix interfaces being prevented in the model

Point Cloud Framework for Rendering 3D Models Using Google Tango

This project seeks to demonstrate the feasibility of point cloud meshing for capturing and modeling three dimensional objects on consumer smart phones and tablets. Traditional methods of capturing objects require hundreds of images, are very slow and consume a large amount of cellular data for the average consumer. Software developers need a starting point for capturing and meshing point clouds to create 3D models as hardware manufacturers provide the tools to capture point cloud data. The project uses Googles Tango computer vision library for Android to capture point clouds on devices with depth-sensing hardware. The point clouds are combined and meshed as models for use in 3D rendering projects. We expect our results to be embraced by the Android market because capturing point clouds is fast and does not carry a large data footprint

INTEREST OF FINITE ELEMENT ANALYSIS TO DETERMINE STRESS FIELDS AT THE SUMMIT OF A VY FLAP ABOUT ONE CLINICAL CASE

International audienceAfter performing a V-Y advancement flap, we observed an unusually shaped necrosis, resembling a keyhole at the apex of the flap. As high closing tensions are an accepted cause of skin necrosis, we developed a mathematical model based on the finite element analysis in order to determine the stress field by simulating the mechanical behavior of human skin during suture and to explain this particular shape of necrosis. For the modeling, a planar nonlinear two-dimensional finite element model was used. The numerical simulation was carried out with Ansys® v12 software. Results are expressed in numerical and graphic form. The shape of the vertical iso-stress line for a stress equal to 18.8 kPa was similar to the necrosis observed in our clinical case. Similarities between the shape of necrosis and the calculated stress field at the apex of the V-Y advancement flap indicate the major role of skin tension in this necrosis. Finite element analysis is an original approach for describing the particular shape of a necrosis. Although many factors can be implicated in skin necrosis, the modeling confirms the role of tension in the necrosis of this particular case

A potential solution to GMAW gas flow optimisation

A number of self-regulating shielding gas valves have been developed to synchronise the shielding gas flow rate to the welding current being used in the gas metal arc welding process (GMAW). These valves make claims to reduce the shielding gas consumption by up to 60%. One such system, the Regula® EWR Pro, has undergone detailed evaluation in an effort to fully understand the benefits that could be obtained. This electromagnetically controlled system necessitates around an extremely fast response valve, which opens and closes continually throughout the welding process. This creates a pulsing of the shielding gas, further reducing consumption whilst maintaining optimal shielding gas flow. The unit has been identified to reduce the initial gas surge at weld initiation and results in a virtually instant decay of gas flow at weld termination. These particular characteristics have been found to be ideally suited to saving shielding gas when carrying out intermittent or stitch welding. It was established that the use of this valve generated deeper penetration in fillet welds, which in turn has highlighted the potential to increase the welding speed, therefore further reducing gas consumption. In addition, a computational model has been developed to simulate the effects of cross drafts. The combination of reducing the gas surge and slow decay with faster welding has been shown to meet the drive for cost savings and improving the carbon footprint

Terrestrial laser scanning and 3D imaging: Heritage case study – The Black Gate, Newcastle Upon Tyne

This paper offers a case study on the recording of a section of wall on a complex heritage building, the Black Gate in Newcastle upon Tyne. The paper adopts case study methodology to assess the appropriateness of using a long range scanner based upon pulse technology for the recording of part of this historic structure and describes the scanning instruments adopted as well as the selection of appropriate software for the pre-processing and documentation. The study offers an overview of the survey planning stages, field operation, and processing of 3D point cloud data using the third party software adopted, including problems encountered. Issues emerging are discussed, in both the 2D and 3D modelling of detailed surfaces from point cloud data, and in the process of software selection, data preparation and export, pre-processing of point cloud data, meshing and the creation of 2D geometry and 3D animations. The paper describes the end results offered as deliverables for this project, and offers recommendations for a working method that can produce data suitable for producing stone-by-stone elevation drawings. The work processes and cost / time indicators are included in this case study and conclusions will consider whether the technique adopted could lead to an improved solution for heritage recording compared to those traditional techniques which are currently employed to produce stone-by-stone elevations. Areas for future research are identified