Fracture Toughness of Welds Using As-Welded-Geometry/SENT Specimens

2016 ◽  
Author(s):  
Mohammed Uddin ◽  
Gery Wilkowski
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Fracture Analysis ◽  
Constant Thickness ◽  
Circumferential Welds ◽  
Ongoing Work ◽  
Specimen Test ◽  
Initial Work ◽  
Edge Notch ◽  
Pipe Geometry

The single-edge notch tension (SENT) test is frequently used for the assessment of the integrity of welds with flaws in them; this is done since the SENT specimen has the same flaw orientation as a surface flaw in the weld, and has similar constraint that affects the brittle-to-ductile transition and upper-shelf value. Traditionally SENT specimens are machined with a rectangular cross-section from the weld, and the thickness might be reduced because of that machining operation. The toughness value of the constant thickness machined specimen is then used in a pipe fracture analysis. Of course real welds have crowns in the roots of the weldment, which are ignored in both the fracture specimen test and the pipe geometry fracture analysis. To assess the importance of the weld crown and root, SENT tests were conducted as an exploratory aspect to determine the effect on toughness. Additionally, assessment of results where the SENT specimen breaks in the weld or base metal outside the weld due to the reinforcing that is usually machined off and ignored were conducted. The use of a full-weldment cross-section in SENT testing can be done for axial seam welds or circumferential welds. The initial work was on axial seam welds, although there is ongoing work for circumferential welds as well.

Sensitivity of Non-Uniform Beams in Depositing Mass Process

2006 ◽  
Author(s):  
Dumitru I. Caruntu
Keyword(s):  
Film Thickness ◽  
Relative Density ◽  
Cross Section ◽  
Natural Frequencies ◽  
Rectangular Cross Section ◽  
Relative Sensitivity ◽  
Constant Thickness ◽  
Thickness Variation ◽  
Slender Beams ◽  
Beam Dimension

This paper deals with the mass deposition influence on the natural frequencies of nonuniform cantilever resonator sensors of linear and parabolic thickness. Resonator sensitivity, defined as fraction of change in frequency per fraction of change in thickness deposition and relative density, was found. A constant thickness mass deposition on all four lateral surfaces of the cantilever of rectangular cross-section was assumed. Euler-Bernoulli theory was used, so only slender beams were considered. Mass deposition on the free end surface of the beams was neglected. The film thickness was considered very small compared to any beam dimension. The film had no contribution to the beam stiffness, only to the mass. Results show that for the same thickness deposition, the sensitivity in the first mode of beams of linear thickness is 2.5 to 3.5 higher when compared to uniform beams. For beams of parabolic thickness variation the relative sensitivity ranges between 1.5 and 2.1.

scholarly journals Hydroelastic waves propagating along a frozen channel with non-uniform thickness of ice

2021 ◽  
Vol 2057 (1) ◽  
pp. 012021
Author(s):  
K N Zavyalova ◽  
K A Shishmarev ◽  
E A Batyaev ◽  
T I Khabakhpasheva
Keyword(s):  
Cross Section ◽  
Elastic Plate ◽  
Rectangular Cross Section ◽  
Normal Modes ◽  
Elastic Beam ◽  
Wave Profile ◽  
Constant Thickness ◽  
Ice Thickness ◽  
Thin Elastic Plate ◽  
Uniform Thickness

Abstract Hydroelastic waves propagating along a channel covered with ice of non-uniform thickness are considered. The channel has a rectangular cross section. The fluid in the channel is inviscid and incompressible. The ice is modeled as a thin elastic plate. The ice thickness changes linearly. The problem is reduced to the problem of the wave profile across the channel, which is solved using the normal modes of an elastic beam with non-uniform thickness. It is shown that with the decrease in the change in the ice thickness, the modes approach the normal modes of an elastic beam with a constant thickness. The behavior of the dispersion relations of the hydroelastic waves depending on the parameter describing the change in the ice thickness is studied.

On Sensitivity of Capacitive Microresonators Near Three Half Natural Frequency

2010 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Martin Knecht
Keyword(s):  
Natural Frequency ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Constant Thickness ◽  
Microcantilever Sensors ◽  
Electrostatically Actuated ◽  
Resonance Frequencies ◽  
Parametric Oscillations ◽  
Deposition Thickness ◽  
Beam Dimension

This paper deals with sensitivity of electrostatically actuated micro resonator sensors near three half natural frequency. Mass deposition changes resonance frequencies of structures. Resonator sensitivity, defined as a fraction of change in frequency per unit deposited mass, can be found for microcantilever sensors electrostatically actuated to include fringe and Casimir effects. These actuation forces produce nonlinear parametric oscillations. Constant thickness mass deposition on all four lateral surfaces of the cantilever of rectangular cross-section was assumed. The Euler-Bernoulli theory was used under the assumption that the beams are slender. Mass deposition on the free end surface of the cantilever was neglected. The deposition thickness was considered uniform and very small compared to any beam dimension. The deposited mass had no contribution to the stiffness, only to the mass. Analytical expression of the sensitivity of electrostatically actuated uniform microcantilever resonators sensor near natural frequency can be determined.

ANALYSIS OF THE GENERAL EQUATIONS OF THE TRANSVERSE VIBRATION OF A PIECEWISE UNIFORM VISCOELASTIC PLATE

2020 ◽  
Vol 7 (3) ◽  
pp. 52-56
Author(s):  
MMATMATISA JALILOV ◽  
◽  
RUSTAM RAKHIMOV ◽  
Keyword(s):  
Cross Section ◽  
Transverse Vibration ◽  
Three Dimensional ◽  
Viscoelastic Plate ◽  
Constant Thickness ◽  
Regional Problem ◽  
Rigid Contact ◽  
Under Construction ◽  
Derivatives Of ◽  
Theoretical Results

This article discusses the analysis of the general equations of the transverse vibration of a piecewise homogeneous viscoelastic plate obtained in the “Oscillation of inlayer plates of constant thickness” [1]. In the present work on the basis of a mathematical method, the approached theory of fluctuation of the two-layer plates, based on plate consideration as three dimensional body, on exact statement of a three dimensional mathematical regional problem of fluctuation is stood at the external efforts causing cross-section fluctuations. The general equations of fluctuations of piecewise homogeneous viscoelastic plates of the constant thickness, described in work [1], are difficult on structure and contain derivatives of any order on coordinates x, y and time t and consequently are not suitable for the decision of applied problems and carrying out of engineering calculations. For the decision of applied problems instead of the general equations it is expedient to use confidants who include this or that final order on derivatives. The classical equations of cross-section fluctuation of a plate contain derivatives not above 4th order, and for piecewise homogeneous or two-layer plates the elementary approached equation of fluctuation is the equation of the sixth order. On the basis of the analytical decision of a problem the general and approached decisions of a problem are under construction, are deduced the equation of fluctuation of piecewise homogeneous two-layer plates taking into account rigid contact on border between layers, and also taking into account mechanical and rheological properties of a material of a plate. The received theoretical results for the decision of dynamic problems of cross-section fluctuation of piecewise homogeneous two-layer plates of a constant thickness taking into account viscous properties of their material allow to count more precisely the is intense-deformed status of plates at non-stationary external loadings.

scholarly journals Designing for People’s Safety on Flooded Streets: Uncertainties and the Influence of the Cross-Section Shape, Roughness and Slopes on Hazard Criteria

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2119
Author(s):  
Luís Mesquita David ◽  
Rita Fernandes de Carvalho
Keyword(s):  
Cross Section ◽  
Overland Flow ◽  
Rectangular Cross Section ◽  
Safety Hazard ◽  
Cross Section Shape ◽  
Section Shape ◽  
Flood Flows ◽  
The Cross ◽  
Flooding Risk

Designing for exceedance events consists in designing a continuous route for overland flow to deal with flows exceeding the sewer system’s capacity and to mitigate flooding risk. A review is carried out here on flood safety/hazard criteria, which generally establish thresholds for the water depth and flood velocity, or a relationship between them. The effects of the cross-section shape, roughness and slope of streets in meeting the criteria are evaluated based on equations, graphical results and one case study. An expedited method for the verification of safety criteria based solely on flow is presented, saving efforts in detailing models and increasing confidence in the results from simplified models. The method is valid for 0.1 m2/s 0.5 m2/s. The results showed that a street with a 1.8% slope, 75 m1/3s−1 and a rectangular cross-section complies with the threshold 0.3 m2/s for twice the flow of a street with the same width but with a conventional cross-section shape. The flow will be four times greater for a 15% street slope. The results also highlighted that the flood flows can vary significantly along the streets depending on the sewers’ roughness and the flow transfers between the major and minor systems, such that the effort detailing a street’s cross-section must be balanced with all of the other sources of uncertainty.

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