M. P. V. Souza

Bio: M. P. V. Souza is an academic researcher from Federal University of Rio de Janeiro. The author has contributed to research in topics: Thermography & Radiographic testing. The author has an hindex of 2, co-authored 4 publications receiving 86 citations.

Detection of lack of fusion weld defects by radiography

Abstract: In this work, radiography was employed as the NDT technique for detection of flaws in circumferential girth welds of steel pipelines used in offshore installations in the petroleum industry. The kind of defect specifically focused was lack of fusion. It is currently accepted in the literature that radiography is not as sensitive as ultrasonics to detect lack of fusion defects. Unfortunately, the radiographic inspection can barely detect lack of fusion and only when it is associated to inclusions and voids of considerable size. However, in a previous article (“Reliability of radiographic inspection of steel pipeline girth welds,” QNDE Conference, 2007), the authors showed that it is possible to detect lack of fusion defects if, in the radiographic tests, the angle of incidence is the same angle that the weld bevel makes with the test piece surface, which means lowering the angle of disorientation between the flaw and the radiographic beam. However, no concerns were made to sizing the defects. Computational simulation was used with XRSIM software to establish the optimal radiographic parameters to reach the lower limit for detection for this kind of defect.

Prediction of Rubble-Stone Masonry Walls Response under Axial Compression Using 2D Particle Modelling

Abstract: To predict the structural behaviour of ancient stone masonry walls is still a challenging task due to their strong heterogeneity. A rubble-stone masonry modeling methodology using a 2D particle model (2D-PM), based on the discrete element method is proposed given its ability to predict crack propagation by taking directly into account the material structure at the grain scale. Rubble-stone (ancient) masonry walls tested experimentally under uniaxial compression loading conditions are numerically evaluated. The stone masonry numerical models are generated from a close mapping process of the stone units and of the mortar surfaces. A calibration procedure for the stone-stone and mortar-mortar contacts based on experimental data is presented. The numerical studies show that the 2D-PM wall models can predict the formation and propagation of cracks, the initial stiffness and the maximum load obtained experimentally in traditional stone masonry walls. To reduce the simulation times, it is shown that the wall lateral numerical model adopting a coarser mortar discretization is a viable option for these walls. The mortar behaviour under compression with lateral confinement is identified as an important micro-parameter, that influences the peak strength and the ductility of rubble-masonry walls under uniaxial loading.

Defect detection in composite coatings by computational simulation aided thermography

Abstract: Thermography is based on the measurement of superficial temperature distribution of an object inspected subjected to tension, normally thermal heat. This measurement is performed with a thermographic camera that detects the infrared radiation emitted by every object. In this work thermograph was simulated by COMSOL software for optimize experimental parameters in composite material coatings inspection.

On field inspection of composite pipes using pulsed phase thermography

Abstract: The pulsed phase thermography (PPT) is becoming a valuable tool on the detection and dimensioning of defects on composite materials. However, the most of the works that adopt the PPT needs very sophisticated equipment to thermal excitation of the specimen and data acquisition. This work uses the concepts of the PPT to inspect sections of fiberglass reinforced epoxy pipes used on adhesively bonded joints applied on the oil industry on extraction and transportation of fluids, using low cost and simple equipment to thermal excitation. A MatLab routine to data processing was used intending to achieve a fast and reliable non‐destructive method to be performed on field. Amplitude and phase images are generated from the infrared images without any pre‐processing technique revealing simulated defects that were impossible to be detected on the original data. A study of how deep the thermal wave can reach along the thickness of this kind of material is also performed trying to estipulate the limits of the technique aiming on the detection of problems on adhesive layers using two heat sources: halogen lamp and industrial air blower. Results support the possibility of implementing a reliable and low cost method of inspection on field to various values of pipe thicknesses found on plants of the oil industry.

Structural Health Monitoring (SHM) and Determination of Surface Defects in Large Metallic Structures using Ultrasonic Guided Waves.

Abstract: Ultrasonic guided wave (UGW) is one of the most commonly used technologies for non-destructive evaluation (NDE) and structural health monitoring (SHM) of structural components. Because of its excellent long-range diagnostic capability, this method is effective in detecting cracks, material loss, and fatigue-based defects in isotropic and anisotropic structures. The shape and orientation of structural defects are critical parameters during the investigation of crack propagation, assessment of damage severity, and prediction of remaining useful life (RUL) of structures. These parameters become even more important in cases where the crack intensity is associated with the safety of men, environment, and material, such as ship’s hull, aero-structures, rail tracks and subsea pipelines. This paper reviews the research literature on UGWs and their application in defect diagnosis and health monitoring of metallic structures. It has been observed that no significant research work has been convened to identify the shape and orientation of defects in plate-like structures. We also propose an experimental research work assisted by numerical simulations to investigate the response of UGWs upon interaction with cracks in different shapes and orientations. A framework for an empirical model may be considered to determine these structural flaws.

Reducing Welding Defects in Turnaround Projects: A Lean Six Sigma Case Study

Abstract: This case study describes how one specialty construction company used the Lean Six Sigma methodology to reduce welding defects in turnaround projects.

Wireless Piping Inspection Vehicle Using Magnetic Adsorption Force

Abstract: A robot is developed which is able to climb on a perpendicular branched piping and moves on the ceiling in the piping with the radio control. This inspection robot adsorbs to the piping using the magnetic adsorption force of a magnetic crawler and moves in piping. Therefore, the crawler should be composed of magnets that have optimal adsorption force. In order to design the crawler, the magnetic adsorption force is analyzed, and the design method of the inspection robot in the piping is shown. The robot mounts a radio control unit and a compact radio camera so as to inspect inside of piping. To validate it, a compact crawler type radio control robot is made, and traveling performance or inspection performance in the piping is examined.

Review on the identification of reputation loss indicators in an onshore pipeline explosion event

Abstract: Pipeline damage consequence assessment is performed to determine the losses due to a failure event, including human, asset, production and environmental loss. Another failure impact – reputation loss – is in contrast commonly excluded due to its qualitative nature, even though pipeline failure events can greatly endanger a pipeline operator's post-accident reputation. Thus, a comprehensive review on the identification of pipeline operator reputation loss indicators due to onshore pipeline explosion was conducted in this article. It aims to identify pipeline owner reputation-threat factors that lead to negative perceptions among stakeholders prior to pipeline damage, as reported in selected onshore pipeline explosion case studies. A total of 30 pipeline accident reports were reviewed, and the factors influencing the stakeholders' perceptions towards the pipeline operator were extracted; 30 factors affecting the pipeline operator's reputation were identified. This review shows the influence of negative perceptions of the stakeholders on the company's reputation loss after an accident. This factor identification process helps the pipeline operator respond appropriately to maintain the company's reputation in the event of pipeline failure. Eventually, a comprehensive consequence assessment for onshore oil and gas pipeline damage can be obtained by incorporating reputation-threat factors.