Structural Integrity Assessment of a Pipeline Subjected to an Underwater Explosion

2011 ◽  
Author(s):  
Paolo Monti ◽  
Caterina Molinari ◽  
Massimiliano Bocciarelli ◽  
Alberto Corigliano ◽  
Stefano Mariani
Keyword(s):  
Structural Integrity ◽  
Underwater Explosion ◽  
Structural Response ◽  
Potential Hazard ◽  
Limit States ◽  
Integrity Assessment ◽  
Definition Of ◽  
Bubble Pulsation ◽  
Numerical Approaches

Several trunklines cross either areas which in the recent past were war theatre or dumping areas used for burying weapons after the last war. The presence of unexploded mines, bombs or torpedoes on the seabed constitutes a potential hazard for the structural integrity of submarine pipelines. Before laying, it is therefore necessary to remove the unexploded charges within a corridor including the route. Risk still remains during the pipeline life, since annual surveys can show evidences of unexploded mines or torpedoes dragged by fishing gears till the protruding pipeline. Consequently, the structural integrity assessment of a submarine pipeline subjected to underwater explosions is of the utmost importance. The aforementioned assessment involves several aspects: the characterization of shock wave and gas bubble pulsation in water; the definition of loading conditions on the pipeline; the characterisation of the strain-rate properties of the steel; the local and global structural analysis; the pipe verification criteria. Aim of this study is to describe how the aforementioned aspects can be managed. Analytical and numerical approaches concerning the assessment of the structural response of the pipeline are presented, and criteria for Serviceability and Accidental Limit States are proposed.

French R&D Program for RPV Aging Management

2004 ◽  
Author(s):  
H. Churier-Bossennec ◽  
D. Moinereau ◽  
P. Todeschini ◽  
C. Faidy ◽  
G. Bezdikian
Keyword(s):  
Structural Integrity ◽  
Probabilistic Approach ◽  
Development Program ◽  
Surveillance Program ◽  
Integrity Assessment ◽  
Large Program ◽  
Periodic Safety ◽  
Long Lifetime ◽  
Definition Of ◽  
Mitigation Methods

Until now French approach for RPV PTS assessment is based on at least 40 years lifetime. This lifetime has been taken into account at each step of the the RPV life: first early in the design, then at each periodic safety demonstration by including the surveillance program, the national and international feedback and R&D results. All of them confirm that all the 3-loop French RPV fulfill the existing criteria for at least 40 years of operation. In order to evaluate their capability to operate for 60 years, an Engineering and Research and Development program has been recently established and engaged by EDF. This large program of activities between all of divisions of EDF is focused on the different fields involved in the risk of fast rupture of the irradiated core vessel. The main purposes of this programme are: • the research of specific data corresponding to a long lifetime of about 60 years; • the studies of new methods to improve the demonstration including several themes such as fluence evaluation, determination of fracture toughness, structural integrity assessment including probabilistic approach, definition of transients; • the evaluation of mitigation methods. This paper contains first a description of what was done at each RPV PTS assessment and an overview of the present program.

Structural analysis of old stone arch bridges

1989 ◽  
Vol 16 (6) ◽  
pp. 789-797 ◽  
Author(s):  
D. K. McNeely ◽  
G. C. Archer ◽  
K. N. Smith
Keyword(s):  
Structural Analysis ◽  
Structural Integrity ◽  
Load Capacity ◽  
Structural Response ◽  
Secondary Effects ◽  
Structural Behaviour ◽  
Limit States ◽  
Significant Deterioration ◽  
Arch Bridges ◽  
Stone Arches

The use of stone arches for bridge construction has generally ceased, but since these structures still exist in modern road systems, their structural integrity is of current concern. This paper presents an analysis technique suited for the thick jointed heritage stone arch bridges found in Canada. The effect of increased mortar joint size on structural response is investigated. The response of a section to eccentric thrust is postulated and the effective section properties are derived. Structural behaviour proceeds from a fixed arch to a two-hinge, a three-hinge, and finally a five-hinge failure mode for a symmetrical arch with midspan loading. A typical load–deflection curve is developed, suitably adjusted for secondary effects due to changes in geometry and material nonlinearity. Stone arch bridges in Canada were constructed with thick mortar joints, which exhibit significant deterioration of stiffness with load eccentricity and, therefore, significant secondary effects; as thickness increases, ultimate strength decreases. A suitable limit states prediction for the load capacity of old stone arches is proposed. Key words: arch, bridge, heritage, limit states, stone, structural analysis.

scholarly journals Remote Monitoring of Floating Covers Using UAV Photogrammetry

2020 ◽  
Vol 12 (7) ◽  
pp. 1118 ◽  
Author(s):  
Leslie Wong ◽  
Benjamin Steven Vien ◽  
Yue Ma ◽  
Thomas Kuen ◽  
Frank Courtney ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Wastewater Treatment Plants ◽  
Health Assessment ◽  
Treatment Plant ◽  
Renewable Resource ◽  
The State ◽  
Integrity Assessment ◽  
Structural Health Assessment ◽  
Aerial Vehicle ◽  
Definition Of

High-density polyethylene (HDPE) is commonly the material of choice for covered anaerobic lagoons (CAL) at wastewater treatment plants. The membrane floats on the wastewater, and hence is called a “floating cover”, and is used for odour control and to harvest the methane-rich biogas as a renewable resource to generate electricity. The floating cover is an expensive and high-value asset that demands an efficient methodology for the determination of a set of engineering quantities for structural integrity assessment. Given the dynamics of the anaerobic activities under the floating cover, the state of deformation of the floating cover is an engineering measurand that is useful for its structural health assessment. A non-contact measurement strategy is preferred as it offers practical and safety-related benefits over other methods. In collaboration with Melbourne Water Corporation (MWC), an unmanned aerial vehicle (UAV) assisted photogrammetry approach was developed to address this need. Following the definition of the appropriate flight parameters required to quantify the state of deformation of the cover, a series of periodic flights were operated over the very large floating covers at MWC’s Western Treatment Plant (WTP) at Werribee, Victoria, Australia. This paper aims to demonstrate the effectiveness and practicality of this inspection technique to determine the state of deformation of the floating covers measured over a ten-month period.

Fracture Mechanics and Non-Destructive Testing for Structural Integrity Assessment

2008 ◽  
Vol 399 ◽  
pp. 27-36 ◽  
Author(s):  
Stojan Sedmak ◽  
Aleksandar Sedmak
Keyword(s):  
Fracture Mechanics ◽  
Structural Integrity ◽  
Strain Analysis ◽  
Destructive Testing ◽  
Testing Procedures ◽  
Integrity Assessment ◽  
Loaded Component ◽  
Analysis Of Failures ◽  
Non Destructive

Fracture mechanics parameters can be applied for the analysis of failures of structures, and also for prevention of failures when defects in a structure are detected and defined. The approach is presented through stages: detection of defects, stress-strain analysis of loaded component, characterization of material properties required for structural integrity assessment and application of convenient procedure. In this way the decision about next use of defective component can be made (to continue the operation, increased care by inspection, exclusion the component from next service, with eventual repair, if possible). Special attention is paid to the most popular testing procedures for crack resistance parameters.

Neuropharmacological Characterization of Dioclea altissima Seed Lectin (DAL) in Mice: Evidence of Anxiolytic-like Effect Mediated by Serotonergic, GABAergic Receptors and NO Pathway

2020 ◽  
Vol 26 (31) ◽  
pp. 3895-3904
Author(s):  
João R.C. Araújo ◽  
Adriana R. Campos ◽  
Marina de Barros M.V. Damasceno ◽  
Sacha A.A.R. Santos ◽  
Maria K.A. Ferreira ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Elevated Plus Maze ◽  
Biological Activities ◽  
Plant Lectins ◽  
Plus Maze ◽  
Marble Burying ◽  
Gabaergic Receptors ◽  
The Central Nervous System ◽  
Hole Board

Background: Plant lectins have shown promising biological activities in the central nervous system (CNS). Objective: This study evaluated the effect of DAL, a lectin isolated from the seeds of the Dioclea altissima species, having binding affinity to D-glucose or D-mannose residues, on mice behavior. Methods: Mice (n=6/group) were treated (i.p.) with DAL (0.25, 0.5 or 1 mg/kg) or vehicle and subjected to several tests (open field/OFT, marble-burying/MBT, hole-board/HBT, elevated plus maze/PMT, tail suspension/ TST, forced swimming/FST or rotarod/RRT). Pizotifen, cyproheptadine, flumazenil, L-NAME, 7-NI, Larginine or yohimbine were administered 15 min before DAL (0.5 mg/kg) and the animals were evaluated on PMT. It was also verified whether the DAL effect depended on its structural integrity and ability to interact with carbohydrates. Results: The results showed there were no neurobehavioral changes in the mice at the RRT, FST and locomotion in the OFT. DAL (0.25, 0.5 or 1 mg/kg) increased the behavior of grooming and rearing in the OFT, head dips in the HBT, pedalling in the TST and decreased the number of marbles hidden in the MBT. In the PMT, DAL (0.25, 0.5 and 1 mg/kg) and Diazepam increased the frequency of entries in the open arms and the time of permanence in the open arms without affecting the locomotor activity. The effect of DAL was dependent on carbohydrate interaction and protein structure integrity and it prevented by pizotifen, cyproheptadine, flumazenil, L-NAME and 7-NI, but not by L-arginine or yohimbine. Conclusion: DAL was found to have an anxiolytic-like effect mediated by the 5-HT and GABAergic receptors and NO pathway.

scholarly journals Experimental Evaluation of Shear Behavior of Stone Masonry Wall

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2313
Author(s):  
Maria Luisa Beconcini ◽  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi ◽  
Benedetta Puccini
Keyword(s):  
Shear Behavior ◽  
Stone Masonry ◽  
Masonry Walls ◽  
Mechanical Parameters ◽  
In Situ Tests ◽  
Capacity Curves ◽  
Historical Structures ◽  
Definition Of

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.

Sign in / Sign up

Export Citation Format

Share Document