scholarly journals Experimental Study of Dynamic Bending Stiffness of ACSR Overhead Conductors

2015 ◽  
Vol 30 (5) ◽  
pp. 2252-2259 ◽  
Author(s):  
Frederic Levesque ◽  
Sylvain Goudreau ◽  
Sebastien Langlois ◽  
Frederic Legeron
Keyword(s):  
Experimental Study ◽  
Bending Stiffness ◽  
Dynamic Bending

scholarly journals Experimental Study on Sandwich Bridge Decks with GFRP Face Sheets and a Foam-Web Core Loaded under Two-Way Bending

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ruili Huo ◽  
Weiqing Liu ◽  
Li Wan ◽  
Yuan Fang ◽  
Lu Wang
Keyword(s):  
Experimental Study ◽  
Energy Dissipation ◽  
Bending Strength ◽  
Bridge Decks ◽  
Sheet Thickness ◽  
Highway Bridges ◽  
Bending Stiffness ◽  
Face Sheet ◽  
Displacement Ductility ◽  
Ultimate Bending Strength

In recent years, the sandwich bridge decks with GFRP face sheets and light weight material core have been widely used in the world due to their advantages of low cost, high strength to weight ratios, and corrosion resisting. However, as the bridge decks, most of them are used in foot bridges rather than highway bridges because the ultimate bending strength and initial bending stiffness are relatively low. To address this issue and expand the scope of use, a simple and innovative sandwich bridge deck with GFRP face sheets and a foam-web core, manufactured by vacuum assisted resin infusion process, is developed. An experimental study was carried out to validate the effectiveness of this panel for increasing the ultimate bending strength and initial bending stiffness under two-way bending. The effects of face sheet thickness, foam density, web thickness, and web spacing on displacement ductility and energy dissipation were also investigated. Test results showed that, compared to the normal foam-core sandwich decks, an average approximately 657.1% increase in the ultimate bending strength can be achieved. Furthermore, the bending stiffness, displacement ductility, and energy dissipation can be enhanced by increasing web thickness, web height, and face sheet thickness or decreasing web spacing.

Dynamic Behavior of Submarine Pipelines Under Laying Operation

1982 ◽  
Vol 104 (4) ◽  
pp. 313-318 ◽  
Author(s):  
N. Suzuki ◽  
N. Jingu
Keyword(s):  
Experimental Study ◽  
Dynamic Behavior ◽  
Water Depth ◽  
Forced Oscillation ◽  
Bending Moment ◽  
Scale Model ◽  
Regular Waves ◽  
Wave Response ◽  
Dynamic Bending

Theoretical and experimental study on dynamic behavior of submarine pipelines under laying operation with articulated stingers is described in this paper. Wave response tests in regular waves and forced oscillation tests in still water were conducted using the 1/20 scale model of 406.4 mm o.d. (16 in. o.d.) pipeline laid in 150 m (500 ft) water depth. The results show that: 1) the maximum dynamic bending moment of pipeline MDmax occur at a stinger roller, 2) dynamic bending moment of pipelines MD at shorter periods are larger than those at longer periods, 3) the values of MD in an over-bend region depend highly upon stinger motion, 4) those of MD in a sag-bend region are less than MD max in an over-bend region, 5) the values of MD/HMY increase as the stinger volume increases and that 6) stinger motion at shorter periods are different from those at longer periods.

Computational Tool for the Dynamic Analysis of Flexible Risers Incorporating Bending Hysteresis

2007 ◽  
Author(s):  
Russell Smith ◽  
Tommie Carr ◽  
Michael Lane
Keyword(s):  
Production Systems ◽  
New Technology ◽  
Fatigue Loading ◽  
Bending Stiffness ◽  
Analysis Tool ◽  
Flexible Pipe ◽  
Recent Developments ◽  
Dynamic Bending ◽  
Increasing Demand ◽  
Bending Response

Non-bonded flexible-pipe risers provide a structurally compliant solution in offshore floating production systems for the recovery of oil & gas. The bending stiffness of the flexible pipe is an important property in designing the riser system to safely withstand extreme and fatigue loading conditions. These risers have two fundamentally different bending stiffness properties that depend on if the riser system is pressurized or depressurized. A depressurized riser has a comparatively small linear bending stiffness. Most riser designs apply this stiffness as its produces conservative (large) bending responses. In recent years, the bending response predicted from the depressurized bending stiffness has proven overly conservative and there has been an increasing demand to consider the larger hysteretic bending stiffness of the pressurized riser. The objective is to reduce the conservatism and achieve an approved safe design. Recent developments have advanced the modeling of flexible riser bending with hysteresis and this capability has now been incorporated into an industry standard finite-element riser analysis tool. This paper describes the background of hysteresis in relation to non-bonded flexible pipes and outlines the methodology of the riser motions software that incorporates bending stiffness with hysteresis. Riser systems where the dynamic bending response is critical to the success of the design are the main applications that will benefit from this new technology. Examples include: i.) The dynamic bending response at the seabed touchdown of a deepwater catenary riser. ii.) Bending at an interface with the riser hang-off or subsea tie-in.

scholarly journals Methodology for the study and prediction of stiffness characteristics during bending rials for the design of adaptive clothing for people with motor disabilities

2021 ◽  
Vol 54 (4) ◽  
pp. 22-29
Author(s):  
Marina V. Zimina ◽  
Anastasia P. Gruzdeva ◽  
Lyubov′ L. Chagina
Keyword(s):  
Experimental Study ◽  
Objective Assessment ◽  
Experimental Studies ◽  
Bending Stiffness ◽  
Operating Conditions ◽  
Design Stage ◽  
Test Results ◽  
Motor Disabilities ◽  
Design Solutions ◽  
Stiffness Characteristics

The article analyses the existing methods of studying the characteristics of bending stiffness. Topicality of improving the methodology for assessing and predicting bending stiffness in relation to the operating conditions of the studied contingent of consumers is substantiated. The methodology includes two main stages – an experimental study of the stiffness characteristics taking into account the characteristics of the range under study and a stage of forecasting the design solutions of the product. Comprehensive experimen-tal studies of the bending characteristics of modern fabrics of the jacket assortment for adaptive clothing of people with motor disabilities have been carried out. For an objective assessment of wear during use, the proposed method implements an additional forced bending of samples in opposite directions in order to bring the test results closer to real operating conditions. The results of experimental studies can be used at the design stage to predict the bending characteristics of the fabrics of the jacket assortment of clothing for people with motor disabilities.

Locomotor design of dolphin vertebral columns: bending mechanics and morphology of Delphinus delphis.

1997 ◽  
Vol 200 (1) ◽  
pp. 65-81 ◽  
Author(s):  
J H Long ◽  
D A Pabst ◽  
W R Shepherd ◽  
W A McLellan
Keyword(s):  
Mechanical Properties ◽  
Vertebral Body ◽  
Vertebral Column ◽  
Mechanical Performance ◽  
Bending Stiffness ◽  
Skeletal Structure ◽  
Lumbar Region ◽  
Bending Tests ◽  
Delphinus Delphis ◽  
Dynamic Bending

The primary skeletal structure used by dolphins to generate the dorsoventral bending characteristic of cetacean swimming is the vertebral column. In the vertebral column of the saddleback dolphin Delphinus delphis, we characterize the static and dynamic mechanical properties of the intervertebral joints, describe regional variation and dorsoventral asymmetries in mechanical performance, and investigate how the mechanical properties are correlated with vertebral morphologies. Using a bending machine that applies an external load (N m) to a single intervertebral segment, we measured the resulting angular deformation (rad) of the segment in both dorsal extension and ventral flexion. Intervertebral segments from the thoracic, lumbar and caudal regions of the vertebral column were tested from five individuals. Using quasi-static bending tests, we measured the initial (low-strain) bending stiffness (N m rad-1) as a function of segment position, direction of bending (extension and flexion) and sequential cutting of intervertebral ligaments. We found that initial bending stiffness was significantly greater in the lumbar region than in adjacent thoracic and caudal regions, and all joints were stiffer in extension than is predicted (r2 = 0.554) by the length and width of the intervertebral disc and the length of the cranial vertebral body in the segment. Stiffness in flexion is predicted (r2 = 0.400) by the width of the nucleus pulposus, the length of the caudal vertebral body in the segment and the height of the transverse processes from the ventral surface of the vertebral body. We also performed dynamic bending tests on intervertebral segments from the lumbo-caudal joint and the joint between caudal vertebrae 7 and 8. Dynamic bending stiffness (N m rad-1) increases with increasing bending amplitude and is independent of bending frequency. Damping coefficient (kg m2 rad-2 s-1) decreases with increasing bending amplitude and frequency. Resilience (% energy return) increases from approximately 20% at low bending amplitudes (+/-0.6 degree) to approximately 50% at high bending amplitudes (+/-2.9 degrees). Based on these findings, the dolphin's vertebral column has the mechanical capacity to help control the body's locomotor reconfigurations, to store elastic energy and to dampen oscillations.

scholarly journals A simple equivalent plate model for dynamic bending stiffness of three-layer sandwich panels with shearing core

2021 ◽  
pp. 116025
Author(s):  
U. Arasan ◽  
F. Marchetti ◽  
F. Chevillotte ◽  
L. Jaouen ◽  
D. Chronopoulos ◽  
...  
Keyword(s):  
Sandwich Panels ◽  
Bending Stiffness ◽  
Plate Model ◽  
Dynamic Bending

Experimental study on the restoration from a tilt-azimuth series for improvement in resolution

1995 ◽  
Vol 53 ◽  
pp. 636-637
Author(s):  
Norio Baba ◽  
Norihiko Ichise ◽  
Syunya Watanabe
Keyword(s):  
Experimental Study ◽  
Spherical Aberration ◽  
Incident Beam ◽  
Optical Parameters ◽  
Beam Tilting ◽  
Illumination Method ◽  
Restoration Method ◽  
Illumination Mode

The tilted beam illumination method is used to improve the resolution comparing with the axial illumination mode. Using this advantage, a restoration method of several tilted beam images covering the full azimuthal range was proposed by Saxton, and experimentally examined. To make this technique more reliable it seems that some practical problems still remain. In this report the restoration was attempted and the problems were considered. In our study, four problems were pointed out for the experiment of the restoration. (1) Accurate beam tilt adjustment to fit the incident beam to the coma-free axis for the symmetrical beam tilting over the full azimuthal range. (2) Accurate measurements of the optical parameters which are necessary to design the restoration filter. Even if the spherical aberration coefficient Cs is known with accuracy and the axial astigmatism is sufficiently compensated, at least the defocus value must be measured. (3) Accurate alignment of the tilt-azimuth series images.

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