Dr Sayeed Hossain has expertise in residual stress analyses. He has extensive experience in applying Neutron diffraction, X-ray diffraction, Incremental centre-hole drilling, deep-hole drilling and finite element analysis (FEA) methods. Sayeed has worked on numerous industrial and academic projects involving residual stresses, their measurements and their influences on part distortions in aerospace industry and on creep formation in power generation sector. He applied different approach to optimizing measurement techniques and advised on the use of FEA concurrent to residual stress measurements for safety critical components. He has worked on the construction of VEQTER residual stress database from design and development to implementation stage. Supervisors: Late Prof David J Smith and Prof Christopher E Truman
Encyclopedia of Renewable and Sustainable Materials, 2020
The particulate composite protective coating has been developed in thick surface layer on a low a... more The particulate composite protective coating has been developed in thick surface layer on a low alloy steels by preplacing titanium carbide (TiC)different ceramic carbide particles into a shallow melt pool produced on a moving sample using traditional conventional tungsten inert gas (TIG) torch melting approach. Protective layers coating ranging in thickness from 0.05 to 1.0 mm are formed, the thickness being determined by different heat input. The composite protective surface was investigated by a diversity of techniques, including scanning electron microscopy (SEM), energy-dispersive x-ray (EDX) and Microhardness testering. This chapter discusses the types of surface morphology or structures which have been produced by preplacing ceramic TiC particles on the substrate of low alloy steels and TIG melting/particle injection process (so called re-solidification process) and considers the effect on upon these structures developed by different heat input which in turn change the mode of dissolution or particle swimming. Special consideration is given to the degree of hardness development on the particulate composite protective surface after re-solidification via TIG torch melting technique
Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robin... more Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robinson 1,a CE Truman 2,b S. Hossain 2,c R. Wimpory 3,d 1Materials and Surface Science Institute, University of Limerick, Ireland. ...
Volume 6: Materials and Fabrication, Parts A and B, 2012
ABSTRACT Residual stresses were predicted and measured in a circular disc containing a partial ri... more ABSTRACT Residual stresses were predicted and measured in a circular disc containing a partial ring weld. This study first created an axisymmetric finite element model so that the process of introducing the ring weld was simulated using thermal and mechanical modelling. The resulting residual stresses were then mapped onto a 3D model which included the necessary mesh and boundary conditions to simulate the process of residual stress measurement using the deep hole drilling method. Then an experimental programme of residual stress measurement using the deep hole drilling method and the neutron diffraction technique was conducted on the welded circular disc. The results from the deep hole drilling measurements matched well with the neutron diffraction results on the original stress field in the ring weld. While comparison between measurements and predicted residual stresses show that predicted hoop stresses are slightly higher than measured, there is in general a fair comparison between measured and predicted residual stress.
Conference Proceedings of the Society for Experimental Mechanics Series, 2011
Residual stress measurements using non-destructive techniques including neutron diffraction and X... more Residual stress measurements using non-destructive techniques including neutron diffraction and X-ray diffraction are dependent on assumptions made in the analysis. For example, the different stress free reference sample and the presence of precipitates in a ...
Page 1. Uncertainties in Triaxial Residual Stress Measurements DM Goudar 1,a , S. Hossain 1,b , C... more Page 1. Uncertainties in Triaxial Residual Stress Measurements DM Goudar 1,a , S. Hossain 1,b , CETruman 1,c , EJ Kingston 2,d and DJSmith 1,e 1Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR UK ...
Volume 6: Materials and Fabrication, Parts A and B, 2008
ABSTRACT Accurate characterization of residual stress in engineering components is important in s... more ABSTRACT Accurate characterization of residual stress in engineering components is important in structural integrity assessment. Two commonly used methods of measuring residual stress include the neutron diffraction technique and the deep-hole drilling (DHD) technique. The former is a well-known nondestructive measurement method and the latter is a semi-invasive technique which is readily available and portable. Both these measurement techniques depend on a number of physical quantities and are therefore sensitive to errors associated with the measured data. The resulting stress uncertainties can easily become significant and compromise the usefulness of the results or lead to misinterpretation of the behaviour of stress distribution. This paper describes briefly the error analysis for both techniques. Results from earlier neutron diffraction and deep hole drilling measurements are used to illustrate the errors. It is found that the average error for both techniques is about ±20MPa. In the case of the neutron diffraction method this error is acceptable for path lengths less than a few centimetres. At greater path lengths the errors become unacceptably large. In contrast the error in the DHD is independent of depth.
ABSTRACT Material fracture toughness data are required to undertake fitness-for-service assessm... more ABSTRACT Material fracture toughness data are required to undertake fitness-for-service assessments of engineering components containing cracks. Calculations of crack driving force in the component are compared with material fracture toughness values to assess the likelihood of subsequent failure. Experimental measurements of fracture toughness are usually made on small specimens extracted from a larger ‘parent’ component following strict experimental guidelines, formulated to ensure measured toughness values in the fracture specimens are appropriate for use in the full-size component. Implicit in this procedure is the assumption that the extracted fracture specimens contain no residual stresses, with any residual stresses in the full-size component being accounted for in the crack driving force calculation. This paper considers a recent conjecture within the structural integrity community that the extracted fracture specimens may themselves contain a residual stress field which may influence measurements of fracture toughness. This could potentially lead to a degree of ‘double accounting’, i.e. the effect of residual stresses may be included in both the material toughness and the crack driving force. This, in turn, could lead to unnecessary conservatism in safety assessments. To explore this conjecture, the results of numerical modelling and neutron diffraction measurements of residual stresses in fracture specimens extracted from two different welded parent components are presented. One of the components is significantly larger than the extracted specimens, with the other being marginally larger than the extracted specimens. Results confirm the intuitive expectation that the residual stresses in specimens extracted from much larger components are negligible, whereas if the dimensions of the extracted specimens are comparable with the larger component then significant residual stresses may remain.
ABSTRACT This paper presents measurements of the in-plane residual stress components through the ... more ABSTRACT This paper presents measurements of the in-plane residual stress components through the wall of a 218mm long, 26mm deep repair weld, offset by 7mm from the centreline of a girth weld joining two type 316H stainless steel pipes approximately 37mm thick. The measurements were obtained using the deep hole drilling technique. Two locations were examined: (i) mid-length of the repair weld and (ii) the stop-end of the repair. Both measurements were taken along the girth weld centreline. The distributions and magnitudes of the measured longitudinal and transverse stress components at the two locations were very similar over the outer half of the pipe wall. Over the inner half of the pipe wall both components of stress were found to be significantly more compressive at the stop-end of the repair than at mid-length. In general, the transverse residual stresses were found to be lower than the longitudinal residual stresses at both locations. The measured stress profiles are compared with predicted residual stresses from a three dimensional finite element analysis for a similar weld repair.
International Journal of Pressure Vessels and Piping, 2012
ABSTRACT The influence of free surfaces, local geometry and plasticity on the residual stress ana... more ABSTRACT The influence of free surfaces, local geometry and plasticity on the residual stress analysis by the deep-hole drilling (DHD) method is addressed in this paper. A finite element (FE) analysis using the commercial software ABAQUS was used to model a number of selected specimens that had been subjected to thermal process conditions that create initial residual stress fields. The essential steps of the DHD method were then simulated at a selected number of locations through the specimens. Two sets of analyses were conducted; one set assumed only that the process of simulating the DHD method was entirely elastic. The second set assumed that the DHD process was elastic–plastic. In the majority of the test cases the conventional DHD method is shown to provide reconstructed in-plane residual stresses that agreed well with the initial residual stresses and did not suffer from expected near free-surface or geometric effects. The results for the out-of-plane residual stresses were however dependent on the assumed state of stress and the interpretation of the axial distortions. The reconstructed out-of-plane residual stresses were shown to have limited agreement with the initial stresses. For the elastic–plastic study, results from a ring welded cylinder were successfully mapped on to a DHD model. A new incremental technique was shown to reconstruct the initial in-plane residual stresses with reasonable accuracy with only limited success for the out-of-plane stress.
Encyclopedia of Renewable and Sustainable Materials, 2020
The particulate composite protective coating has been developed in thick surface layer on a low a... more The particulate composite protective coating has been developed in thick surface layer on a low alloy steels by preplacing titanium carbide (TiC)different ceramic carbide particles into a shallow melt pool produced on a moving sample using traditional conventional tungsten inert gas (TIG) torch melting approach. Protective layers coating ranging in thickness from 0.05 to 1.0 mm are formed, the thickness being determined by different heat input. The composite protective surface was investigated by a diversity of techniques, including scanning electron microscopy (SEM), energy-dispersive x-ray (EDX) and Microhardness testering. This chapter discusses the types of surface morphology or structures which have been produced by preplacing ceramic TiC particles on the substrate of low alloy steels and TIG melting/particle injection process (so called re-solidification process) and considers the effect on upon these structures developed by different heat input which in turn change the mode of dissolution or particle swimming. Special consideration is given to the degree of hardness development on the particulate composite protective surface after re-solidification via TIG torch melting technique
Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robin... more Page 1. Residual stress and microstructural variations in thick aluminium alloy forgings JS Robinson 1,a CE Truman 2,b S. Hossain 2,c R. Wimpory 3,d 1Materials and Surface Science Institute, University of Limerick, Ireland. ...
Volume 6: Materials and Fabrication, Parts A and B, 2012
ABSTRACT Residual stresses were predicted and measured in a circular disc containing a partial ri... more ABSTRACT Residual stresses were predicted and measured in a circular disc containing a partial ring weld. This study first created an axisymmetric finite element model so that the process of introducing the ring weld was simulated using thermal and mechanical modelling. The resulting residual stresses were then mapped onto a 3D model which included the necessary mesh and boundary conditions to simulate the process of residual stress measurement using the deep hole drilling method. Then an experimental programme of residual stress measurement using the deep hole drilling method and the neutron diffraction technique was conducted on the welded circular disc. The results from the deep hole drilling measurements matched well with the neutron diffraction results on the original stress field in the ring weld. While comparison between measurements and predicted residual stresses show that predicted hoop stresses are slightly higher than measured, there is in general a fair comparison between measured and predicted residual stress.
Conference Proceedings of the Society for Experimental Mechanics Series, 2011
Residual stress measurements using non-destructive techniques including neutron diffraction and X... more Residual stress measurements using non-destructive techniques including neutron diffraction and X-ray diffraction are dependent on assumptions made in the analysis. For example, the different stress free reference sample and the presence of precipitates in a ...
Page 1. Uncertainties in Triaxial Residual Stress Measurements DM Goudar 1,a , S. Hossain 1,b , C... more Page 1. Uncertainties in Triaxial Residual Stress Measurements DM Goudar 1,a , S. Hossain 1,b , CETruman 1,c , EJ Kingston 2,d and DJSmith 1,e 1Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR UK ...
Volume 6: Materials and Fabrication, Parts A and B, 2008
ABSTRACT Accurate characterization of residual stress in engineering components is important in s... more ABSTRACT Accurate characterization of residual stress in engineering components is important in structural integrity assessment. Two commonly used methods of measuring residual stress include the neutron diffraction technique and the deep-hole drilling (DHD) technique. The former is a well-known nondestructive measurement method and the latter is a semi-invasive technique which is readily available and portable. Both these measurement techniques depend on a number of physical quantities and are therefore sensitive to errors associated with the measured data. The resulting stress uncertainties can easily become significant and compromise the usefulness of the results or lead to misinterpretation of the behaviour of stress distribution. This paper describes briefly the error analysis for both techniques. Results from earlier neutron diffraction and deep hole drilling measurements are used to illustrate the errors. It is found that the average error for both techniques is about ±20MPa. In the case of the neutron diffraction method this error is acceptable for path lengths less than a few centimetres. At greater path lengths the errors become unacceptably large. In contrast the error in the DHD is independent of depth.
ABSTRACT Material fracture toughness data are required to undertake fitness-for-service assessm... more ABSTRACT Material fracture toughness data are required to undertake fitness-for-service assessments of engineering components containing cracks. Calculations of crack driving force in the component are compared with material fracture toughness values to assess the likelihood of subsequent failure. Experimental measurements of fracture toughness are usually made on small specimens extracted from a larger ‘parent’ component following strict experimental guidelines, formulated to ensure measured toughness values in the fracture specimens are appropriate for use in the full-size component. Implicit in this procedure is the assumption that the extracted fracture specimens contain no residual stresses, with any residual stresses in the full-size component being accounted for in the crack driving force calculation. This paper considers a recent conjecture within the structural integrity community that the extracted fracture specimens may themselves contain a residual stress field which may influence measurements of fracture toughness. This could potentially lead to a degree of ‘double accounting’, i.e. the effect of residual stresses may be included in both the material toughness and the crack driving force. This, in turn, could lead to unnecessary conservatism in safety assessments. To explore this conjecture, the results of numerical modelling and neutron diffraction measurements of residual stresses in fracture specimens extracted from two different welded parent components are presented. One of the components is significantly larger than the extracted specimens, with the other being marginally larger than the extracted specimens. Results confirm the intuitive expectation that the residual stresses in specimens extracted from much larger components are negligible, whereas if the dimensions of the extracted specimens are comparable with the larger component then significant residual stresses may remain.
ABSTRACT This paper presents measurements of the in-plane residual stress components through the ... more ABSTRACT This paper presents measurements of the in-plane residual stress components through the wall of a 218mm long, 26mm deep repair weld, offset by 7mm from the centreline of a girth weld joining two type 316H stainless steel pipes approximately 37mm thick. The measurements were obtained using the deep hole drilling technique. Two locations were examined: (i) mid-length of the repair weld and (ii) the stop-end of the repair. Both measurements were taken along the girth weld centreline. The distributions and magnitudes of the measured longitudinal and transverse stress components at the two locations were very similar over the outer half of the pipe wall. Over the inner half of the pipe wall both components of stress were found to be significantly more compressive at the stop-end of the repair than at mid-length. In general, the transverse residual stresses were found to be lower than the longitudinal residual stresses at both locations. The measured stress profiles are compared with predicted residual stresses from a three dimensional finite element analysis for a similar weld repair.
International Journal of Pressure Vessels and Piping, 2012
ABSTRACT The influence of free surfaces, local geometry and plasticity on the residual stress ana... more ABSTRACT The influence of free surfaces, local geometry and plasticity on the residual stress analysis by the deep-hole drilling (DHD) method is addressed in this paper. A finite element (FE) analysis using the commercial software ABAQUS was used to model a number of selected specimens that had been subjected to thermal process conditions that create initial residual stress fields. The essential steps of the DHD method were then simulated at a selected number of locations through the specimens. Two sets of analyses were conducted; one set assumed only that the process of simulating the DHD method was entirely elastic. The second set assumed that the DHD process was elastic–plastic. In the majority of the test cases the conventional DHD method is shown to provide reconstructed in-plane residual stresses that agreed well with the initial residual stresses and did not suffer from expected near free-surface or geometric effects. The results for the out-of-plane residual stresses were however dependent on the assumed state of stress and the interpretation of the axial distortions. The reconstructed out-of-plane residual stresses were shown to have limited agreement with the initial stresses. For the elastic–plastic study, results from a ring welded cylinder were successfully mapped on to a DHD model. A new incremental technique was shown to reconstruct the initial in-plane residual stresses with reasonable accuracy with only limited success for the out-of-plane stress.
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Papers by Sayeed Hossain