Search results for "STRAIN GAUGE"
showing 10 items of 52 documents
Influence of different restorative materials on the stress distribution in dental implants
2018
Background To assist clinicians in deciding the most suitable restorative materials to be used in the crowns and abutment in implant rehabilitation. Material and methods For finite element analysis (FEA), a regular morse taper implant was created using a computer aided design software. The implant was inserted at the bone model with 3 mm of exposed threads. An anatomic prosthesis representing a first maxillary molar was modeled and cemented on the solid abutment. Considering the crown material (zirconia, chromium-cobalt, lithium disilicate and hybrid ceramic) and abutment (Titanium and zirconia), the geometries were multiplied, totaling eight groups. In order to perform the static analysis,…
Strain Measurement on Composites: Errors due to Rosette Misalignment
2002
Electrical resistance strain gauges are increasingly used for the determination of the strain field in composite components. The effect of the angular misalignment of a strain gauge rosette on the determination of the strains in a composite material is investigated in this paper. The theoretical analysis shows that the strain error along the principal material directions depends on the difference of principal strains, on the angular misalignment of the rosette and on the angle between the maximum principal strain and the fibre direction. The paper also shows experimental evidence for the theoretical analysis.
Stress distribution of complete-arch implant-supported prostheses reinforced with silica-nylon mesh
2019
Made available in DSpace on 2020-12-12T01:20:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Background: This study evaluated the presence of a silica-nylon mesh and two cantilever lengths on the biomechanical behavior of complete-arch implant-supported prostheses. Material and Methods: Twenty-four (24) complete mandibular arch implant-supported prostheses were divided into 4 groups according to the presence of reinforcing mesh (with or without) and the cantilever length (molar-15 mm or premolar-5 mm). The specimens were submitted to strain gauge analysis (30-kgf, 10 s) at different points (molar and premolar). Three-dimensional models were created based on the in vitro spec…
Effects of clearance on thick, single-lap bolted joints using through-the-thickness measuring techniques
2011
Composite materials have increasingly become more common in ground transportation. As this occured thicker panels, as compared to composite panels used in aviation, become necessary in order to withstand high impact loads and day to day degradation. The effectiveness of these panels was often limited by the strength of the joint in which the panel was attached to the frame of the vehicle. Investigating methods of reducing strain concentrations within these joints would increase the effectiveness in using composite materials in ground transportation applications by increasing the load necessary for joint failure to occur. In this study, fiber optic strain gages were embedded in a composite p…
Stress distribution in fixed mandibular prostheses fabricated by CAD/CAM and conventional techniques: Photoelastic and strain gauge analyses
2019
Made available in DSpace on 2020-12-12T00:55:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-01 The aim of this study was to evaluate the distribution of stress in complete fixed mandibular prostheses with infrastructures (IE) fabricated with different materials and techniques, under compressive force. A model of an edentulous mandible, which received five 4x11 mm external hexagon implants between the mental foramens, was fabricated. The groups were divided into: Group I - IE in nickel-chromium with an acrylic resin occlusal coating; Group II - IE in nickel-chromium with a ceramic occlusal coating; Group III - IE milled in zirconia with a ceramic coating. For the photoelastic m…
EMBEDDED STRAIN GAUGES: EFFECT OF THE STRESS NORMAL TO THE GRID
2005
: In general, a strain gauge embedded in a model is subjected to a stress normal to the grid, whereas a gauge on the external surface is free from such a stress. This paper concerns the effect of the stress normal to the grid on the output of the strain gauge; usually, the influence of such a stress has a negligible effect, however, in some cases a notable influence has been noted. Therefore, the output of the strain gauge is determined in function of the strains in the plane of the gauge, ɛl and ɛt, and of the stress, σn, normal to the grid. The analysis shows that the output of the strain gauge is influenced by the coupled effect of transverse sensitivity and pressure sensitivity of the …
Local reinforcement effect of embedded strain gauges
2010
The reinforcement effect of strain gauges installed on low Young's modulus materials has received attention by many researchers with respect to both strain gauges installed on the surface [1,2] and embedded inside the material [3,4]. In the case of strain gauges installed on the surface, the evaluation of the local reinforcement effect gives [5] the following correction coefficient C, i.e. the ratio between the actual strain (without the strain gauge) and the strain ' measured by the strain gauge: * ' 1 sg s E C E (1) being * sg g , sg sg sg sg sg sg t L L E E L t t (2) where Esg is the Young’s modulus of the strain gauge, * Esg is a characteristic of the strain gauge which gives the strain…
Vibration Detector based on GMR Sensors
2007
Up to now, vibrations have been mostly sensed by measuring displacement, velocity and acceleration. The most common types of vibration sensors are piezoelectric, capacitive, null-balance, strain gage, optoelectronic, resonance beam or piezoresistive. We present a low cost and low power vibration detector based on the measurement of magnetic field variations induced in a recent SS501 GMR magnetic sensor, which has never been applied for that. Vibrations on small ferromagnetic pieces disturb the Earth's magnetic field. These weak perturbations can be detected and measured over the assumed constant Earth's magnetic field, which is uniform over a wide area. A novel array configuration of 3 half…
CiNetStrain - Wireless Strain Gauge Network - Calibration and Reliability Measurements
2013
Wireless sensor networks can be extended to include numerous different sensing devices. Strain gauges are the most common nondestructive sensing elements for measuring surface strain. This paper discusses the design, for the wireless CiNet network, of a strain gauge measurement system, which would make strain measurements more flexible while opening new targets of application in addition to those that traditional wired strain measuring systems can offer. The calibration and validation of the wireless strain measurements as well as energy consumption issues are also brought under observation.
Advances in Strain Gauge Measurement on Composite Materials
2010
This article gives an overview on the application of strain gauge techniques to the analysis of the strains in composite materials. The orthotropic behaviour of the composite influences the performance of strain gauges that are calibrated for use on isotropic materials. The article considers therefore the typical topics of the strain gauge technology applied to composites with particular reference to the compensation of thermal output, the measurement of the coefficients of thermal expansion, the determination of the strain and stress state, the influence of the misalignment error, the reinforcement effect, the determination of the stress intensification factor, the analysis of residual str…