cranfield university mahadi abd murad an integrated structural ...

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out using the Compact Rio system with Labview software, together with strain gauges. Real time monitoring and data acquisition are able to provide the diagnosis and prognosis of the structural system at any given time. If the repair is not able to restore the damage, then the related pipe shall be mitigated immediately. Otherwise, the integrity management programme will then focus on the life extension programme which can contribute to more cost savings for pipeline operators. Maintenance Strategy Cathodic Protection Pipe Replacement Life Extension Cost Benefit Analysis Repair Procedures Standards Fitness for Purpose Assessment (e.g. BS / ASTM etc) Recoating Mitigation Root Cause Forensics Repair Options Structural Integrity Pipeline Integrity Hydrostatic Testing Cleaning and Inhibiting 2 Stress Corrosion Cracking (SCC) SCADA Weather related In-Line Inspection Assessment Monitoring 3 rd Party Damage/Dent/Manufacturing Defect Fatigue Equipment Malfunction and Operation Errors Structural Health Monitoring External / Internal Corrosion FEA / ABAQUS Simulation Coating Survey Cathodic Protection Figure 1.1: Summary of Pipeline Integrity Management programme
1.1 Objectives Knowing this background, the objectives of this PhD study are shown below; 1. To analyse blunt defect (external corrosion) behaviour in a composite based pipeline repair system using a numerical finite element analysis (ABAQUS) and validate by experiment. 2. To prove the integrity of bonding between the base structure (pipeline) that contains defects and the reinforced composite wraps as a reliable solution in the elastic load transfers or distributions. 3. To develop a methodology for measuring the coefficient of thermal expansion of test materials (i.e. steel and composite). These objectives were accomplished by designing and fabricating the simple and yet versatile pressure and temperature steel test rig. One of the test rig segments was introduced with an artificial arc-shaped defect on it that mimics real corrosion. Next, stress concentration and stress strain distribution studies were carried out using ABAQUS software and the strain distribution study was validated by the experimental work after the composite repair was carried out on the defect area. In the strain measurement experimental work, rectangular strain gauges with 120 and 350 Ohms were bonded on a steel test rig and composite respectively and the data acquisition was carried out using the robust Compact Rio system together Labview software. Under the influence of the actual internal pressure loading, the numerical study of blunt defect (external corrosion) behaviour in the composite based repair was validated and the integrity of bonding between the base structure and composite repair was analysed and discussed. Finally, by using a simple surface temperature detector or infrared laser thermometer, together with rectangular strain gauges and strain indicator, the coefficient of thermal expansion (CTE) of the steel specimen (i.e. part of the steel test rig) and the 3
Page 1: CRANFIELD UNIVERSITY MAHADI ABD MUR
Page 4 and 5: ABSTRACT One of the most common pro
Page 7 and 8: TABLE OF CONTENTS ABSTRACT ........
Page 9 and 10: 3.7.1 Introduction ................
Page 11: 5.6 Summary and Conclusions .......
Page 14 and 15: Figure 3.1: Schematic diagram of th
Page 16 and 17: Figure 5.4: The average temperature
Page 18 and 19: NOMENCLATURES ACFM Alternating Curr
Page 21: 1 INTRODUCTION One of the most comm
Page 25 and 26: The methodology of this integrated
Page 27 and 28: Chapter 6 contains the summary and
Page 29 and 30: period of the major part of the exi
Page 31 and 32: Figure 2.2: Reported interest in de
Page 33 and 34: Figure 2.4: Dent damage caused by v
Page 35 and 36: presented current practices, recent
Page 37 and 38: Energy Workforce Sdn Bhd (2011) cla
Page 39 and 40: available provides real time detect
Page 41 and 42: 2.3.3 Reliability Analysis of Infor
Page 43 and 44: Figure 2.9: Pipeline failure probab
Page 45 and 46: 2.3.3.1 NDT Reliability and POD cur
Page 47 and 48: increase in the yield limit of stee
Page 49 and 50: the SCC assessment in their integri
Page 51 and 52: Manufacturers such as Walkers Techn
Page 53 and 54: Company L.P, 2005); Aquawrap ® pro
Page 55 and 56: monitoring, inspection, and damage
Page 57 and 58: 2.6.2 Aims of Structural Health Mon
Page 59 and 60: Figure 2.16: Application fields and
Page 61 and 62: egistered by the piezoelectric sens
Page 63 and 64: discretization error. Round-off err
Page 65 and 66: notches and Neuber‘s is better fo
Page 67 and 68: maximum local stress at discontinui
Page 69 and 70: De Carvalho (2005) concludes that t
Page 71 and 72: accurate simulation of loading espe
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Based on the above facts, the opera
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3 FINITE ELEMENT ANALYSIS (FEA) IN
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Figure 3.2: Schematic diagram of th
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In this modelling work (i.e. compos
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This partition toolset also helps u
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Figure 3.6: Mesh control using Swee
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Figure 3.7: Schematic representatio
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discretization. Therefore, in this
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According to Staten et al. (2010b),
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3.5 The influence of pressure on th
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each pressure value remains constan
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Axial Stress, σa (S22) was referre
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Figure 3.14 shows a graph of analyt
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the notch defect is found to be in
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One of the contributions of this st
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Table 3.4: Convergence tests on var
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Figures 3.16 and 3.17 show that the
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Figure 3.20 shows that as the relat
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3.7.4 Concluding Remarks A biaxial
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yarns change and lateral contact be
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For predicting E2 and Gl2, a number
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Where: Ar = weight of one sheet of
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Where; The Stiffness matrix is trad
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simulations for the hoop strain at
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Figure 3.24: Finding the hoop stres
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Table 3.8: The effect of repair len
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four up to 18 layers. In this study
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hoop and axial stress concentration
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Table 3.11: Predicted Elastic Const
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Table 3.13: Axial Stress v/s L/W ra
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Hoop Stress (MPa) Figure 3.3: Hoop
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However, Frost (2008) and Alexander
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Table 3.17: Ratio of Axial Stress N
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axial load (e.g. buried pipelines t
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3.10 Numerical Strain Analysis of C
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Figure 3.36 shows the contours befo
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Stress Concentration Factor 2 1.8 1
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In fact, for Notch 40 with 18 plies
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this second approach (i.e. the expe
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4.2.2 Strain Gauge Selection and Cr
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Finally, a method used to calculate
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Where, and are the maximum and mini
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should be between 20 and 28 bar and
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welded weld neck flange at both end
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Figure 4.7: Sensor and heating elem
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Figure 4.9: A summary of data acqui
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One of the objectives of doing this
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Figure 4.14: A schematic diagram of
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Table 4.1: Strain gauge readings at
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microstrain 3.00E-04 2.50E-04 2.00E
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However, the axial load transfer is
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Mircostrain 500 450 400 350 300 250
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Since the defect is not a flat notc
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Again, the epoxy resin plays a sign
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Table 4.4: Study at the defect area
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Mircostrain 300 250 200 150 100 50
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Mircostrain 600 500 400 300 200 100
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14.25% in hoop strain and 23.5% in
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consideration for the selection of
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5.4 Methodology of Thermal Expansio
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Figure 5.1: Some preventive measure
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5.4.1 The Fundamentals of the Therm
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5.5 Analysis of Results 5.5.1 The t
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Thermal Output (strain ) 0.0002 0.0
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(Strain ,ε) Figure 5.12: Coefficie
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(Strain ,ε) 0.0002 0.00018 0.00016
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Table 5.1: The strain readings afte
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maximum shear strain increase as th
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The above results show that shear s
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shear strains becomes more stable a
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for future safe design and operatio
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has been fully cured. Poor surface
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6.3 Primary PhD Achievements The ea
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In Chapter 5, the CTE was determine
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ASM International (2002), "Thermal
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Bucinell, R. B. (2001), Calculating
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Proceedings of OMAE'01 20th Interna
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Greenwood, R. (2002), UKOPA Pipelin
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Kotrechko, S. A., Krasovskii, A. Y.
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Mousavi, S. E., Xiao, H. and Sukuma
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Raju, I. S. and Newman, J. C. (1986
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Tennyson, R. C. and Mufti, A. A. (2
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Xue, L., Widera, G. E. O. and Sang,
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General Technical Specifications: T
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Photos of the Design and Build of t
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Composite Installation Process usin
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APPENDIX 3 - STRAIN GAUGE INSTALLAT
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Figure 7: Mylar tape was stuck onto
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Figure 19: Repeating the above proc
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2) Electrical Insulation Test Resul
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