Ahmad Rahbar-Ranji - Academia.edu (original) (raw)
Papers by Ahmad Rahbar-Ranji
Journal of Ship Production and Design
_ Ultimate strength of thin steel plates was studied under shear loading when pitting corrosion a... more _ Ultimate strength of thin steel plates was studied under shear loading when pitting corrosion and cracking occur simultaneously. Nonlinear finite element method was used and the effects of different geometrical parameters, such as crack position, crack length, pit depth, pit diameter, number of the pits, and the inclination angle of the crack, were investigated. It was found that the degree of the pitting (DOP) significantly reduces the ultimate shear strength of the pitted plates when the corrosion is low. For high amount of corrosion, the reduction of the ultimate shear strength remains the same regardless of the amount of the DOP. In plates with short cracks, the crack length has no influence on the reduction of the ultimate shear strength. Also, it was found that the position of the crack is more effective than the length of the crack on the reduction of the ultimate shear strength of the cracked plates. In the cracked-pitted plates, there was no interaction between crack and pit for extremes value of DOP. For low value of DOP, the ultimate shear strength of the cracked-pitted plate was the same as the cracked plate, and for large value of DOP, it is the same as pitted plate. Introduction According to a study performed between 2002 and 2008 by American Bureau of Shipping (ABS) (“Review of Current Practices of Fracture” 2012), majority of reported fractures of the ships were structural failures, such as weld defect, buckling, fracture, and cracking. Cracks and corrosion are two more common defects, which are the main reasons of the failure of the aged steel structures. Plates and stiffened plates are the main structural elements in many structures, including airplanes, bridges, offshore structures, and ships. Ultimate strength evaluation of these structural elements is crucial for rational design of structures, such as Load Resistance Factor Design (LRFD) methods in civil engineering and Ultimate Strength (UTS) evaluation in ship structure. Many studies are carried out to evaluate ultimate strength of intact and damaged plates/ stiffened plates under in-plane compressive stress. Ranji (2012) studied ultimate strength of plate with general corrosion under in-plane compression. He proposed a spectrum for random generation of corroded surface and ultimate strength of corroded plate was evaluated using computer code ANSYS. Ranji and Zarookian (2015) analyzed ultimate strength of cracked stiffened plates with cracks having different stiffeners numerically.
Transactions of The Canadian Society for Mechanical Engineering, Oct 20, 2022
Journal of The Institution of Engineers (India): Series C
Journal of Materials Engineering and Performance
The main objective of this study is to investigate experimentally the effect of polyurea coating ... more The main objective of this study is to investigate experimentally the effect of polyurea coating on fatigue strength of grade-A marine steel (Mild steel). Some preliminary specimens are prepared by different cutting and surface finishing methods, using two types of primer. Based on roughness measurement of surface and pull-off test results, the milling method for cutting and grinding machine method for surface preparation with Rayston as a primer are used. Mechanical properties of steel and coating are determined by applying tensile tests on five specimens. The results of tensile tests show that polyurea coating is low-strength, high-ductile material with good energy absorption capability. Then thirty specimens are fabricated and high-cycle axial fatigue tests with a stress ratio of 0.05 and maximum stress as a fraction of yield stress are employed. The fatigue strength of coated specimens can be as more than 128% of uncoated specimens in high-cycle fatigue. This is due to the high absorption of energy by coating when the applied stress is in the elastic range of steel. In low cycle fatigue tests, the results of coated specimens are almost the same as for uncoated specimens. It was concluded that the type of primer has a very significant effect on the adhesion and fatigue strength of coated specimens.
World Academy of Science, Engineering and Technology, International Journal of Civil and Environmental Engineering, 2016
When subsea pipelines are laid down on the uneven seabed or buried in the seafloor, they may expe... more When subsea pipelines are laid down on the uneven seabed or buried in the seafloor, they may experience upheaval buckling. This condition, which is associated with high temperature and high pressure (HT/HP) of oil in the pipeline leads to large displacement. Finally, bending moment and effective axial force are produced. This way, the cross section of the pipeline may experience failure. In this research, a pipeline on the seabed is simulated employing ABAQUS software, and various influential factors such as the friction coefficient of seabed soil, external and internal hydrostatic pressure and temperature changes in the process of creating upheaval buckling are assessed. The results show that the friction coefficient of soil have much more effect than the other parameters. Furthermore, the pipeline would be unstable when the efficacious axial force increases.
Journal of Adhesion Science and Technology, 2021
In this study, tension fatigue tests of grade-A marine mild steel with epoxy type of coating were... more In this study, tension fatigue tests of grade-A marine mild steel with epoxy type of coating were carried out and the corresponding S–N curves with a survival probability of 97.5% are derived. Comp...
Ships and Offshore Structures, 2014
Old steel structures are more vulnerable to buckling, yielding and fracture due crack and corrosi... more Old steel structures are more vulnerable to buckling, yielding and fracture due crack and corrosion. Predicting residual ultimate strength of plates with crack damage is of crucial importance for health monitoring and condition assessment of aged structures. In this work a series of nonlinear finite-element method is employed for an ultimate strength analysis of steel stiffened plates with a transverse crack. Influential parameters, including plate thickness, type and size of stiffeners, crack length and longitudinal/transverse positions of crack are varied and more than 240 models are studied. It is found that presence of a transverse crack in a thick stiffened plate is more crucial than a thin plate and longitudinal position of centre crack has not a considerable influence on ultimate strength reduction. For thin plate, ultimate strength reduction in edge crack is more than centre crack. Size of stiffeners, thickness of plate and type of stiffeners has no influence on reduction of ultimate strength.
Journal of The Institution of Engineers (India): Series C, 2014
The dynamic effect of moving loads on structures is treated as a dynamic magnification factor whe... more The dynamic effect of moving loads on structures is treated as a dynamic magnification factor when resonant is not imminent. Studies have shown that the calculated magnification factors from field measurements could be higher than the values specified in design codes. It is the main aim of present paper to investigate the applicability and accuracy of a rule-based expression for calculation of dynamic magnification factor for lifting appliances used in marine industry. A steel box shape girder of a crane is considered and transient dynamic analysis using computer code ANSYS is implemented. Dynamic magnification factor is calculated for different loading conditions and compared with rule-based equation. The effects of lifting speeds, acceleration, damping ratio and position of cargo are examined. It is found that rule-based expression underestimate dynamic magnification factor.
Ocean Engineering, 2012
Abstract Corrosion is one of the time dependent detrimental phenomena which reduces strength of s... more Abstract Corrosion is one of the time dependent detrimental phenomena which reduces strength of structures and leads to catastrophic failures. All rules and regulations concerning strength of corroded plates are based on uniform thickness reduction. To estimate residual strength of corroded structures, typically a much higher level of accuracy is required, since, the actual corroded plate has irregular surfaces. There is little study on strength analysis of corroded plate with irregular surfaces especially as a function of corrosion parameters. It is the main aim of present work to study ultimate strength of corroded steel plates with irregular surfaces under in-plane compression. Nonlinear finite element method is employed to determine ultimate strength of corroded steel plates with irregular surfaces. Comparing the results with ultimate strength of corroded plates with uniform thickness, a reduction factor is introduced. Having done this, ultimate strength of corroded plates could be evaluated easily as a function of corrosion conditions.
Ocean Engineering, 2013
The aim of present work is to investigate the characteristics of interactions of different buckli... more The aim of present work is to investigate the characteristics of interactions of different buckling modes of flat-bar stiffened panels. Literature-based and rules-based expressions for assessing buckling strength of stiffened plates are studied. Energy method is employed for the analyses of selected buckling modes of stiffened plates including plate buckling, torsional buckling, web buckling and interactions of them when either plate or stiffener or both are under compression. Results are compared with numerical solutions using finite element method and available expressions to identify the applicability and accuracy of selected expressions for certain conditions. It is found that some of the given expressions for buckling analyses of stiffened plates have limited applicability.
Journal of Mechanics, 2012
Element Free Galerkin method was used to analyze bending of thin plates with variable thickness r... more Element Free Galerkin method was used to analyze bending of thin plates with variable thickness resting on one parameter elastic foundation. Thickness of plate is considered as linearly varying in one direction. Formulation could be applied to plates of any shape with general boundary conditions and loadings. Convergence of solution was examined for different number of nodes, thickness variation and foundation parameters. It was found that for deflection good results were achieved even with small number of nodes regardless of boundary condition, thickness variation and foundation parameters. Accuracy of method is checked against available results and good agreements were found. Applicability of method is demonstrated by solving numerical examples with different boundary conditions, thickness and foundation parameters, and loadings.
Computers & Structures, 1998
This study intends to investigate the vibration behavior of a thin square orthotropic plate resti... more This study intends to investigate the vibration behavior of a thin square orthotropic plate resting on non-uniform elastic foundation and its thickness varying in one or two directions. By using the classical plate theory and employing element free Galerkin method, it is shown that the fundamental frequency coefficients obtained are in good agreement with available results in the literature. The effects of thickness variation, foundation parameter and boundary conditions on frequency are investigated. The results show that the method converges very fast regardless of parameters involved.
Chemical and Petroleum Engineering, 1988
Applied Mathematics and Computation, 2012
The present study aims at investigating nonlinear free vibration of thermally buckled functionall... more The present study aims at investigating nonlinear free vibration of thermally buckled functionally graded nanobeam. The nonlocal nonlinear Euler-Bernoulli beam theory as well as linear eigenmodes of a functionally graded nanobeam vibrating around the first buckling configuration are employed to derive a system of ordinary differential equations via the Galerkin method. Semi-analytical solutions are obtained based on both the homotopy perturbation method and the variational iteration method. Results show that the difference between nonlinear and linear frequencies increases with a rise in the maximum lateral initial deflection, small scale parameter value, and index of the power law. Investigating the effect of the ratio of length to thickness on the variance between the nonlinear and linear frequencies shows that the aspect ratio makes no difference on the classical ratio of nonlinear to linear frequencies although the difference between the nonlocal nonlinear and linear frequencies decreases with a rise in the aspect ratio. In contrast to the ratio of the first nonlinear frequency to the first linear one which will decrease if compressive axial load increases, the values of the compressive axial load which are beyond the load bearing capacity of the functionally graded nanobeam do not affect the ratio of the second nonlinear to linear frequencies.
Ocean Engineering, 2012
Abstract Energy method is used for tripping analysis of asymmetric stiffeners in stiffened plates... more Abstract Energy method is used for tripping analysis of asymmetric stiffeners in stiffened plates. The shape of normalized warping function of stiffener is proposed as a strain distribution for sideways bending and classical plate theory is used for out-of-plane deflection. Strain distribution and elastic tripping stress of different angle bars and permanent means of access structures are calculated and compared with finite element method. It is found that for slender angle bars rigid web or flange assumption for out-of-plane deflection is justified. For angle bars proposed strain distribution based on normalized warping function and previously suggested strain distribution based on bending theory are exactly the same. However, for permanent means of access structures, the proposed strain distribution has better agreement than previously suggested strain distribution. For angle bars and permanent means of access structures with high ratio of web height to length, some discrepancy arises between proposed strain distribution and finite element method due to shear deformation.
Journal of Failure Analysis and Prevention, 2016
Yielding, excessive deformation, brittle fracture, fatigue, and elastic buckling are different mo... more Yielding, excessive deformation, brittle fracture, fatigue, and elastic buckling are different modes of failure of structures. Buckling or instability occurs in structures under compressive stresses. Corrosion is a timedependent degradation which reduces load-bearing capacity. This article investigates the detrimental effect of corrosion on reduction of elastic buckling strength of angle beams with irregular random surfaces. Different corrosion patterns and corrosion parameters are considered. Comparing the results with those available in the literature, it indicates that simulation technique used in this study has good accuracy and applicability for simulation of irregular random surfaces of corroded structures. It also shows that neglecting irregular random surface of corroded angle beams could leads up to 6% overestimation of buckling load. It is found that irregularity of surface has little influence on reduction of buckling load when roughness is low, however, for high values of roughness, the more roughness of surface the lower buckling strength of angle beams.
Journal of Ship Production and Design
The main aim of present study was to determine the ultimate strength of cracked and corroded plat... more The main aim of present study was to determine the ultimate strength of cracked and corroded plates under uniform in-plane compression. Corrosion is considered as pitting-type corrosion at one side of the plate with a central longitudinal crack. Nonlinear finite element analysis using commercial computer code, ANSYS, is used to determine the ultimate strength of deteriorated plates. Different geometrical parameters, including the aspect ratio (AR) and thickness of the plate, number of pits, pit depth-to-thickness ratio, and crack length, are considered. It is found that the AR of plates have great influence on the ultimate strength of cracked-pitted plates. Because of the position and orientation of the crack, the length of central longitudinal crack has no influence on ultimate strength reduction of cracked and cracked-pitted plates. The results show that regardless of the number of pits and crack length, in thin plates where buckling controls failure modes at ultimate strength, th...
Archive of Applied Mechanics
Journal of Ship Production and Design
_ Ultimate strength of thin steel plates was studied under shear loading when pitting corrosion a... more _ Ultimate strength of thin steel plates was studied under shear loading when pitting corrosion and cracking occur simultaneously. Nonlinear finite element method was used and the effects of different geometrical parameters, such as crack position, crack length, pit depth, pit diameter, number of the pits, and the inclination angle of the crack, were investigated. It was found that the degree of the pitting (DOP) significantly reduces the ultimate shear strength of the pitted plates when the corrosion is low. For high amount of corrosion, the reduction of the ultimate shear strength remains the same regardless of the amount of the DOP. In plates with short cracks, the crack length has no influence on the reduction of the ultimate shear strength. Also, it was found that the position of the crack is more effective than the length of the crack on the reduction of the ultimate shear strength of the cracked plates. In the cracked-pitted plates, there was no interaction between crack and pit for extremes value of DOP. For low value of DOP, the ultimate shear strength of the cracked-pitted plate was the same as the cracked plate, and for large value of DOP, it is the same as pitted plate. Introduction According to a study performed between 2002 and 2008 by American Bureau of Shipping (ABS) (“Review of Current Practices of Fracture” 2012), majority of reported fractures of the ships were structural failures, such as weld defect, buckling, fracture, and cracking. Cracks and corrosion are two more common defects, which are the main reasons of the failure of the aged steel structures. Plates and stiffened plates are the main structural elements in many structures, including airplanes, bridges, offshore structures, and ships. Ultimate strength evaluation of these structural elements is crucial for rational design of structures, such as Load Resistance Factor Design (LRFD) methods in civil engineering and Ultimate Strength (UTS) evaluation in ship structure. Many studies are carried out to evaluate ultimate strength of intact and damaged plates/ stiffened plates under in-plane compressive stress. Ranji (2012) studied ultimate strength of plate with general corrosion under in-plane compression. He proposed a spectrum for random generation of corroded surface and ultimate strength of corroded plate was evaluated using computer code ANSYS. Ranji and Zarookian (2015) analyzed ultimate strength of cracked stiffened plates with cracks having different stiffeners numerically.
Transactions of The Canadian Society for Mechanical Engineering, Oct 20, 2022
Journal of The Institution of Engineers (India): Series C
Journal of Materials Engineering and Performance
The main objective of this study is to investigate experimentally the effect of polyurea coating ... more The main objective of this study is to investigate experimentally the effect of polyurea coating on fatigue strength of grade-A marine steel (Mild steel). Some preliminary specimens are prepared by different cutting and surface finishing methods, using two types of primer. Based on roughness measurement of surface and pull-off test results, the milling method for cutting and grinding machine method for surface preparation with Rayston as a primer are used. Mechanical properties of steel and coating are determined by applying tensile tests on five specimens. The results of tensile tests show that polyurea coating is low-strength, high-ductile material with good energy absorption capability. Then thirty specimens are fabricated and high-cycle axial fatigue tests with a stress ratio of 0.05 and maximum stress as a fraction of yield stress are employed. The fatigue strength of coated specimens can be as more than 128% of uncoated specimens in high-cycle fatigue. This is due to the high absorption of energy by coating when the applied stress is in the elastic range of steel. In low cycle fatigue tests, the results of coated specimens are almost the same as for uncoated specimens. It was concluded that the type of primer has a very significant effect on the adhesion and fatigue strength of coated specimens.
World Academy of Science, Engineering and Technology, International Journal of Civil and Environmental Engineering, 2016
When subsea pipelines are laid down on the uneven seabed or buried in the seafloor, they may expe... more When subsea pipelines are laid down on the uneven seabed or buried in the seafloor, they may experience upheaval buckling. This condition, which is associated with high temperature and high pressure (HT/HP) of oil in the pipeline leads to large displacement. Finally, bending moment and effective axial force are produced. This way, the cross section of the pipeline may experience failure. In this research, a pipeline on the seabed is simulated employing ABAQUS software, and various influential factors such as the friction coefficient of seabed soil, external and internal hydrostatic pressure and temperature changes in the process of creating upheaval buckling are assessed. The results show that the friction coefficient of soil have much more effect than the other parameters. Furthermore, the pipeline would be unstable when the efficacious axial force increases.
Journal of Adhesion Science and Technology, 2021
In this study, tension fatigue tests of grade-A marine mild steel with epoxy type of coating were... more In this study, tension fatigue tests of grade-A marine mild steel with epoxy type of coating were carried out and the corresponding S–N curves with a survival probability of 97.5% are derived. Comp...
Ships and Offshore Structures, 2014
Old steel structures are more vulnerable to buckling, yielding and fracture due crack and corrosi... more Old steel structures are more vulnerable to buckling, yielding and fracture due crack and corrosion. Predicting residual ultimate strength of plates with crack damage is of crucial importance for health monitoring and condition assessment of aged structures. In this work a series of nonlinear finite-element method is employed for an ultimate strength analysis of steel stiffened plates with a transverse crack. Influential parameters, including plate thickness, type and size of stiffeners, crack length and longitudinal/transverse positions of crack are varied and more than 240 models are studied. It is found that presence of a transverse crack in a thick stiffened plate is more crucial than a thin plate and longitudinal position of centre crack has not a considerable influence on ultimate strength reduction. For thin plate, ultimate strength reduction in edge crack is more than centre crack. Size of stiffeners, thickness of plate and type of stiffeners has no influence on reduction of ultimate strength.
Journal of The Institution of Engineers (India): Series C, 2014
The dynamic effect of moving loads on structures is treated as a dynamic magnification factor whe... more The dynamic effect of moving loads on structures is treated as a dynamic magnification factor when resonant is not imminent. Studies have shown that the calculated magnification factors from field measurements could be higher than the values specified in design codes. It is the main aim of present paper to investigate the applicability and accuracy of a rule-based expression for calculation of dynamic magnification factor for lifting appliances used in marine industry. A steel box shape girder of a crane is considered and transient dynamic analysis using computer code ANSYS is implemented. Dynamic magnification factor is calculated for different loading conditions and compared with rule-based equation. The effects of lifting speeds, acceleration, damping ratio and position of cargo are examined. It is found that rule-based expression underestimate dynamic magnification factor.
Ocean Engineering, 2012
Abstract Corrosion is one of the time dependent detrimental phenomena which reduces strength of s... more Abstract Corrosion is one of the time dependent detrimental phenomena which reduces strength of structures and leads to catastrophic failures. All rules and regulations concerning strength of corroded plates are based on uniform thickness reduction. To estimate residual strength of corroded structures, typically a much higher level of accuracy is required, since, the actual corroded plate has irregular surfaces. There is little study on strength analysis of corroded plate with irregular surfaces especially as a function of corrosion parameters. It is the main aim of present work to study ultimate strength of corroded steel plates with irregular surfaces under in-plane compression. Nonlinear finite element method is employed to determine ultimate strength of corroded steel plates with irregular surfaces. Comparing the results with ultimate strength of corroded plates with uniform thickness, a reduction factor is introduced. Having done this, ultimate strength of corroded plates could be evaluated easily as a function of corrosion conditions.
Ocean Engineering, 2013
The aim of present work is to investigate the characteristics of interactions of different buckli... more The aim of present work is to investigate the characteristics of interactions of different buckling modes of flat-bar stiffened panels. Literature-based and rules-based expressions for assessing buckling strength of stiffened plates are studied. Energy method is employed for the analyses of selected buckling modes of stiffened plates including plate buckling, torsional buckling, web buckling and interactions of them when either plate or stiffener or both are under compression. Results are compared with numerical solutions using finite element method and available expressions to identify the applicability and accuracy of selected expressions for certain conditions. It is found that some of the given expressions for buckling analyses of stiffened plates have limited applicability.
Journal of Mechanics, 2012
Element Free Galerkin method was used to analyze bending of thin plates with variable thickness r... more Element Free Galerkin method was used to analyze bending of thin plates with variable thickness resting on one parameter elastic foundation. Thickness of plate is considered as linearly varying in one direction. Formulation could be applied to plates of any shape with general boundary conditions and loadings. Convergence of solution was examined for different number of nodes, thickness variation and foundation parameters. It was found that for deflection good results were achieved even with small number of nodes regardless of boundary condition, thickness variation and foundation parameters. Accuracy of method is checked against available results and good agreements were found. Applicability of method is demonstrated by solving numerical examples with different boundary conditions, thickness and foundation parameters, and loadings.
Computers & Structures, 1998
This study intends to investigate the vibration behavior of a thin square orthotropic plate resti... more This study intends to investigate the vibration behavior of a thin square orthotropic plate resting on non-uniform elastic foundation and its thickness varying in one or two directions. By using the classical plate theory and employing element free Galerkin method, it is shown that the fundamental frequency coefficients obtained are in good agreement with available results in the literature. The effects of thickness variation, foundation parameter and boundary conditions on frequency are investigated. The results show that the method converges very fast regardless of parameters involved.
Chemical and Petroleum Engineering, 1988
Applied Mathematics and Computation, 2012
The present study aims at investigating nonlinear free vibration of thermally buckled functionall... more The present study aims at investigating nonlinear free vibration of thermally buckled functionally graded nanobeam. The nonlocal nonlinear Euler-Bernoulli beam theory as well as linear eigenmodes of a functionally graded nanobeam vibrating around the first buckling configuration are employed to derive a system of ordinary differential equations via the Galerkin method. Semi-analytical solutions are obtained based on both the homotopy perturbation method and the variational iteration method. Results show that the difference between nonlinear and linear frequencies increases with a rise in the maximum lateral initial deflection, small scale parameter value, and index of the power law. Investigating the effect of the ratio of length to thickness on the variance between the nonlinear and linear frequencies shows that the aspect ratio makes no difference on the classical ratio of nonlinear to linear frequencies although the difference between the nonlocal nonlinear and linear frequencies decreases with a rise in the aspect ratio. In contrast to the ratio of the first nonlinear frequency to the first linear one which will decrease if compressive axial load increases, the values of the compressive axial load which are beyond the load bearing capacity of the functionally graded nanobeam do not affect the ratio of the second nonlinear to linear frequencies.
Ocean Engineering, 2012
Abstract Energy method is used for tripping analysis of asymmetric stiffeners in stiffened plates... more Abstract Energy method is used for tripping analysis of asymmetric stiffeners in stiffened plates. The shape of normalized warping function of stiffener is proposed as a strain distribution for sideways bending and classical plate theory is used for out-of-plane deflection. Strain distribution and elastic tripping stress of different angle bars and permanent means of access structures are calculated and compared with finite element method. It is found that for slender angle bars rigid web or flange assumption for out-of-plane deflection is justified. For angle bars proposed strain distribution based on normalized warping function and previously suggested strain distribution based on bending theory are exactly the same. However, for permanent means of access structures, the proposed strain distribution has better agreement than previously suggested strain distribution. For angle bars and permanent means of access structures with high ratio of web height to length, some discrepancy arises between proposed strain distribution and finite element method due to shear deformation.
Journal of Failure Analysis and Prevention, 2016
Yielding, excessive deformation, brittle fracture, fatigue, and elastic buckling are different mo... more Yielding, excessive deformation, brittle fracture, fatigue, and elastic buckling are different modes of failure of structures. Buckling or instability occurs in structures under compressive stresses. Corrosion is a timedependent degradation which reduces load-bearing capacity. This article investigates the detrimental effect of corrosion on reduction of elastic buckling strength of angle beams with irregular random surfaces. Different corrosion patterns and corrosion parameters are considered. Comparing the results with those available in the literature, it indicates that simulation technique used in this study has good accuracy and applicability for simulation of irregular random surfaces of corroded structures. It also shows that neglecting irregular random surface of corroded angle beams could leads up to 6% overestimation of buckling load. It is found that irregularity of surface has little influence on reduction of buckling load when roughness is low, however, for high values of roughness, the more roughness of surface the lower buckling strength of angle beams.
Journal of Ship Production and Design
The main aim of present study was to determine the ultimate strength of cracked and corroded plat... more The main aim of present study was to determine the ultimate strength of cracked and corroded plates under uniform in-plane compression. Corrosion is considered as pitting-type corrosion at one side of the plate with a central longitudinal crack. Nonlinear finite element analysis using commercial computer code, ANSYS, is used to determine the ultimate strength of deteriorated plates. Different geometrical parameters, including the aspect ratio (AR) and thickness of the plate, number of pits, pit depth-to-thickness ratio, and crack length, are considered. It is found that the AR of plates have great influence on the ultimate strength of cracked-pitted plates. Because of the position and orientation of the crack, the length of central longitudinal crack has no influence on ultimate strength reduction of cracked and cracked-pitted plates. The results show that regardless of the number of pits and crack length, in thin plates where buckling controls failure modes at ultimate strength, th...
Archive of Applied Mechanics