Analysis of Cracks and Stresses of Welded Attachments on Full-Scale Plate Girder under Fatigue Loading

2006 ◽  
pp. 459-462
Author(s):  
Myung Gu Lee ◽  
Seung Yong Lee ◽  
Cheol Woo Park
Keyword(s):  
Fatigue Loading ◽  
Full Scale ◽  
Plate Girder

Analysis of Cracks and Stresses of Welded Attachments on Full-Scale Plate Girder under Fatigue Loading

2006 ◽  
Vol 324-325 ◽  
pp. 459-462 ◽  
Author(s):  
Myung Gu Lee ◽  
Seung Yong Lee ◽  
Cheol Woo Park
Keyword(s):  
Fatigue Damage ◽  
Fatigue Cracks ◽  
Steel Structure ◽  
Fatigue Loading ◽  
Design Criterion ◽  
Full Scale ◽  
Parent Metal ◽  
Girder Bridges ◽  
Fatigue Design ◽  
Plate Girder

In steel structure systems such as plate girder bridges and framed structures, fatigue damage used to occur at welded areas rather than primary structural members. These damages and behaviors of the welded attachments need to be extensively investigated so that the fatigue design criterion can effectively control the fatigue damage of steel structure systems. This study utilized a full-scale plate girder on which various welding attachments were mounted. The welded attachments investigated herein included flange gussets, web gussets, vertical stiffeners, and cover plates. The fatigue cracks initiated at the longitudinal end of joint area of the weld bead and the parent metal where stress was significantly concentrated. The initiated fatigue cracks developed along the weld path and then, propagated to the parent metal in the direction perpendicular to the principal stress. The fatigue cracks developed even under a compressive stress when a significant residual stress was experienced from the welding. The fatigue strengths of the each welded attachment were evaluated and compared with the current fatigue design specifications in AASHTO [1] and JSSC [2].

Smart Monitoring of a Full-scale Composite Hydrofoil Manufactured using Automated Fibre Placement under High Cycle Fatigue

2021 ◽  
Author(s):  
Md Shamsuddoha ◽  
Gangadhara B. Prusty ◽  
Phyo Thu Maung ◽  
Andrew W. Phillips ◽  
Nigel St John
Keyword(s):  
Optical Fibre ◽  
Structural Integrity ◽  
Measurement Data ◽  
Fatigue Loading ◽  
Full Scale ◽  
Automated Manufacturing ◽  
Optical Fibre Sensors ◽  
Modal Response ◽  
Composites Materials ◽  
Improved Performance

Abstract Fibre reinforced composites materials offer a pathway to produce passive shape adaptive smart marine propellers, which have improved performance characteristics over traditional metallic alloys. Automated Fibre Placement (AFP) technology can provide a leap forward in Cyber-Physical automated manufacturing, which is essential for the implementation and operation of smart factories in the marine propeller industry towards Industry 4.0 readiness. In this paper, a comprehensive structural health monitoring (SHM) routine was performed on an AFP full-scale composite hydrofoil to gain confidence in its dynamic and structural performances through a number of active and passive sensors. The hydrofoil was subjected to constant amplitude flexural fatigue loading in a purpose-built test rig for 105 cycles. The hydrofoil was embedded with distributed optical fibre sensors (DOFS), traditional electrical strain gauges and linear variable displacement transducers (LVDTs). Both microelectromechanical system (MEMS) and piezoelectric (PZT) accelerometers were used to conduct experimental modal analyses (EMA) to observe changes in the modal response of the hydrofoil at regular intervals throughout the fatigue program. The hydrofoils modal response, as well as the stiffness measured using both displacements and strains, remained unchanged over the fatigue loading regime demonstrating the structural integrity of the hydrofoil. The optical fibre sensors endured the fatigue test cycles showing their robustness under fatigue loads. Furthermore, the sensing systems demonstrated the potential of being utilised as a useful maintenance tool combining their adaptability with automated manufacturing during manufacturing through integration within the hydrofoil, a structural test framework for performance measurement, data acquisition and analytics for visualization, and the prospect of decision making for maintenance requirement during any onset in structural performance.

Comparing Fatigue Strength From Full Scale Blade Tests With Coupon-Based Predictions

2002 ◽  
Vol 124 (4) ◽  
pp. 404-411 ◽  
Author(s):  
Hans van Leeuwen ◽  
Don van Delft ◽  
John Heijdra ◽  
Henk Braam ◽  
Eric R. Jørgensen ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Large Deformation ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Full Scale ◽  
Rotor Blades ◽  
Slope Parameter ◽  
Bending Tests ◽  
Testing Laboratories ◽  
Stiffness Reduction

In order to get a deeper understanding of the blade-to-blade variations and to determine the statistical distribution of the fatigue strength of rotor blades, 37 small rotor blades have been tested in static and fatigue loading. The blades are 3.4 m commercially available blades adapted to the needs of the project. In addition to these blade tests, coupons of the blade material have been tested. The tests have encompassed static flapwise bending tests, flapwise fatigue tests at two different sections of the blade, and edgewise fatigue tests. Since some blades could be re-used after a first test, a total number of 42 blade tests has been carried out in three different testing laboratories. The blades showed large deformation, development of creep and stiffness reduction. After correction for these phenomena, the fatigue strength of the blades was predicted very well by the classical Goodman relation using the well-known slope parameter of 10.

Full-Scale Laboratory Evaluation of the Effectiveness of Subgrade Soil Stabilization Practices for Portland Cement Concrete Pavements Patching Applications

2020 ◽  
Vol 2674 (5) ◽  
pp. 465-474
Author(s):  
Ali Behnood ◽  
Jan Olek
Keyword(s):  
Soil Stabilization ◽  
Fatigue Loading ◽  
Full Scale ◽  
Laboratory Evaluation ◽  
Concrete Pavements ◽  
Portland Cement Concrete ◽  
Flowable Fill ◽  
Stabilized Soil ◽  
Adequate Quality ◽  
Base Course

Adequate quality of subgrade under patched areas can extend the service life of concrete pavements and reduce their maintenance costs. In this study, the performance of various subgrade stabilization scenarios was evaluated and compared with each other in a full-scale laboratory-based setup. For this purpose, a test box with the footprint of 6 × 6 ft and a height of 4 ft was constructed using C steel channels. The test box was used to investigate the effects of various types of soil stabilization methods, such as chemical (cement) stabilization, use of aggregate base course (ABC), geogrid (GG) and geotextile (GT) with ABC, GT with cement-stabilized soil, GT with in-situ compacted soil, flowable fill, and lean concrete. The test results showed that all stabilization techniques successfully improved the performance of the subgrade layer by decreasing the deformation under the fatigue loading representing a single axle load of 9,000 lbf/tire. The use of GT with aggregate-based layers was found to significantly reduce the amount of settlement. Subgrade layers stabilized with GG also experienced lower values of deformations compared with the unmodified (control) section. However, GG was not as effective as GT. The use of cement-treated aggregate and lean concrete reduced the deformations to negligible levels.

scholarly journals Mechanical Behaviors and Fatigue Performances of Ballastless Tracks Laid on Long-Span Cable-Stayed Bridges with Different Arrangements

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4195 ◽  
Author(s):  
Xingwang Sheng ◽  
Weiqi Zheng ◽  
Zhihui Zhu
Keyword(s):  
Cross Section ◽  
High Speed ◽  
Fatigue Loading ◽  
Full Scale ◽  
Mechanical Behaviors ◽  
Suspension Point ◽  
Load Pressure ◽  
Long Span ◽  
Track Slab ◽  
Cable Stayed Bridges

In this paper, we present a new attempt to lay ballastless tracks on long-span cable-stayed bridges on high-speed railways. The arrangements of ballastless tracks laid on cable-stayed bridges can be divided into two conditions: (i) across the cable suspension-point cross-section or (ii) in discontinuity at the cable suspension-point cross-section. At present, there is a lack of in-depth research on ballastless tracks laid on long-span cable-stayed bridges, especially on the mechanical behaviors and fatigue performances of the ballastless tracks with different arrangements. For this paper, a segmental model of a long-span cable-stayed bridge was designed and built, on which full-scale ballastless tracks with two different arrangements were arranged. A series of fatigue tests and post-fatigue loading tests were carried out based on the two selected full-scale ballastless tracks. Some conclusions were drawn as follows. For the longitudinal end of the ballastless track, which is far from the loading positions, the interlayers of the ballastless tracks tend to warp up relatively, and the compressive pressures at the interlayers are also unloaded. However, there is no void or gap formed at the interlayers of the longitudinal end of the track slab due to the precompression of the rubber isolation layer. For the center of the track slab, which is close to the loading positions, the compressive deformations occur at the interlayers, and the pressures at interlayers are also increased. The maximum compressive deformation is less than 0.5 mm under the standard train axle load (170 kN), and it cannot affect the high-speed trains’ operation. With the increase of the post-fatigue loading, the load-displacement curves and the load-pressure variation curves of the ballastless tracks show apparent nonlinearity. Moreover, with the increase of the fatigue loading cycles, the compressive stiffness enhancement or degradation of the ballastless tracks are not noticeable. That is to say, the ballastless tracks laid on the long-span cable-stayed bridges with different arrangements have good mechanical behaviors, and their fatigue performances can also be guaranteed after bearing repeated loadings.

The Rationale for Update of S-N Curves for Single Sided Girth Welds for Risers and Pipelines in DNV GL RP C-203 Based on Fatigue Performance of More Than 1700 Full Scale Fatigue Test Results

2018 ◽  
Author(s):  
Agnes Marie Horn ◽  
Inge Lotsberg ◽  
Oddvin Orjaseater
Keyword(s):  
Deep Water ◽  
Fatigue Testing ◽  
Fatigue Loading ◽  
Full Scale ◽  
Fatigue Performance ◽  
Test Results ◽  
Severe Fatigue ◽  
Adequate Quality ◽  
Two Phases ◽  
Girth Welds

Deep-water tendon and riser systems are often subjected to severe fatigue loading from waves, currents and vessel movements. The girth welds between successive lengths of pipe or at pipe terminations represent fatigue-critical features where failure would be catastrophic. Hence, validation fatigue testing by full scale pipes of the most critical welds are often performed to ensure adequate quality and/or to document a better S-N curves than those available in standards today like DNVGL-RP-C203 [1] and BS7608 [2]. To better understand the fatigue performance with respect to identify trends, dependencies and critical features that influence the fatigue performance, a JIP on Fatigue of Girth Welds were initiated in 2011. Two phases have been conducted and a total of 1700 full scale one sided girth welds, mostly run by Stress Engineering, have been statistically analyzed. The test data has been interrogated to investigate the effect of as-welded condition, OD ground, OD/ID ground, un-reeled pipe, reeled pipe, thickness and effect of misalignment. Based on these analyses, new S-N curves for risers and pipelines have been included in DNVGL-RP-C203 for non-reeled girth welds. This paper presents the findings and trends from the JIP work which has been the rationale for the updates of girth welds in section 2.10 in DNVGL-RP-C203 2016 edition.

Fatigue Qualification of Heavy Wall Line Pipe and Girth Weld for High Pressure Applications

2013 ◽  
Author(s):  
Philippe P. Darcis ◽  
Noe Mota ◽  
Enrique Garcia ◽  
Israel Marines-Garcia ◽  
Hector M. Quintanilla ◽  
...  
Keyword(s):  
High Pressures ◽  
Fatigue Loading ◽  
Fatigue Tests ◽  
Performance Comparison ◽  
Full Scale ◽  
Fatigue Performance ◽  
Thick Wall ◽  
Test Machine ◽  
Line Pipe ◽  
Pipe Materials

As the offshore oil & gas industry moves into deeper waters, more and more offshore projects, specifically the subsea, riser and flowline designs, rely on heavy wall line pipe materials. These pipe materials must be capable of operating in stringent working conditions such as high pressures, high temperatures, large deformations, fatigue loading, sour environments, etc. Within this context, ExxonMobil Development Company and Tenaris have jointly conducted a detailed technical assessment of the mechanical and fatigue performance of the newly developed heavy wall X65 line pipe (LP) developed by Tenaris. The main goal of such project is to evaluate and demonstrate via full-scale testing the fatigue performance of this new generation of heavy wall line pipe materials and the associated girth weld also recently developed by Tenaris. Although conclusive fatigue performance results at ID are not included in the present paper, the comprehensive test/qualification plan also includes a fatigue performance comparison at ID and OD. The present work clearly demonstrates weldability of this Heavy Wall X65 (273 mm OD × 46 mm WT) line pipe. A narrow-groove bevel welding procedure utilizing the STT® process for the root pass and single torch GMAW process for hot-pass, fill, and cap has been successfully developed. Four full scale fatigue tests were also successfully conducted using a resonant fatigue test machine. The presented fatigue results help demonstrate a realistic level of fatigue performance achievable with this thick wall LP/girth weld technology which will help facilitate assessment of riser/flowline design feasibility in ultra-deep water applications and/or high pressures fields.

Full Scale Monitoring Marco Polo Tension Leg Platform

2007 ◽  
Author(s):  
Radboud van Dijk ◽  
Henk van den Boom
Keyword(s):  
Low Frequency ◽  
Fatigue Loading ◽  
Full Scale ◽  
Loop Current ◽  
Tension Leg Platform ◽  
Design Data ◽  
Monitoring Campaign ◽  
Wind Speeds ◽  
Vortex Induced Vibrations ◽  
Marco Polo

Installed 160 miles South of New Orleans in 1300 m of water, the Marco Polo Tension Leg Platform is subjected to an extensive monitoring campaign to benchmark design data and methods. The purpose of the full scale monitoring campaign is to evaluate the design in operation exposed to hurricane and loop-current conditions. Interests comprise the high and low frequency modes of motion, the fatigue loading of the platform and the dynamic behavior of the tendons and risers with focus on vortex induced vibrations. To evaluate these results wind, wave and current conditions are closely monitored. The monitoring system was in operation during the passage of hurricanes Ivan, Katrina and Rita. Although Marco Polo was extremely close to the center of these severe hurricanes, no significant damage was inflicted to the platform, even though wind speeds in excess of 138 mph and maximum wave heights over 28 m were measured. However, very valuable data was collected on the wave, wind, current, as well as on the response of the TLP during the Hurricane conditions.

Superaccelerated Pavement Testing on Full-Scale Concrete Slabs

2005 ◽  
Vol 1940 (1) ◽  
pp. 112-124
Author(s):  
Chul Suh ◽  
Jeffrey L. Y. Lee ◽  
David W. Fowler ◽  
Kenneth H. Stokoe
Keyword(s):  
Fatigue Life ◽  
Fatigue Testing ◽  
Fatigue Loading ◽  
Stress Path ◽  
Full Scale ◽  
Concrete Slabs ◽  
Rigid Pavement ◽  
Scale Field ◽  
Stress Ratios ◽  
Pavement Testing

Several full-scale rigid pavement slabs were constructed and tested under constant cyclic loading for fatigue. To provide the comparable maximum applied stress to number of cycles to failure ( S-N) relationships for the full-scale field slabs, laboratory beam fatigue testing was conducted before field testing with the use of the same concrete mix designs. The superaccelerated pavement testing technique that was developed at the University of Texas was used in the field. The stationary dynamic deflectometer (SDD) was used to load the full-scale concrete slabs. To monitor the response of the rigid pavements, accelerometers and linear variable differential transformers were installed, and dynamic and permanent displacements of slabs were recorded during the entire testing period. All test slabs reached fatigue failure under the interior loading configuration using the SDD. This field loading system was found to be a practical and effective tool for testing the full-scale rigid pavement system. During fatigue loading, cracks began at the bottom of the slabs at the loading locations and propagated along the bottom of the slab centerline, which was the maximum stress path. Vertical crack propagation at the edge and stress redistribution occurred for the part of the slab's fatigue life. The concept of equivalent fatigue life was applied to correct the effect of the different stress ratios between the field and the laboratory testing. The laboratory beams and full-scale field slabs showed an almost identical S-N relationship after the correction for the variance of stress ratio.

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