A. Kallmeyer - Academia.edu (original) (raw)
Papers by A. Kallmeyer
Notched Izod impact tests were conducted on wet and dry specimens of a pultruded, glass fiber-rei... more Notched Izod impact tests were conducted on wet and dry specimens of a pultruded, glass fiber-reinforced polymer compos-ite after thermal cycling between 25 and −50ºC. Specimens were impacted following the application of 50, 150, and 300 thermal cycles. The results indicate that moisture initially had a benefi-cial effect on the notch toughness, probably due to a reduction in residual stresses from matrix swelling. After 300 thermal cycles, the beneficial effect of moisture was negated, likely due to an increase in damage from freeze/thaw expansion of the water, and a reduction in the overall moisture state in the composite. Fur-ther research is needed to quantify the damage accumulation during low-temperature thermal cycling.
The prediction of fatigue life or allowable stress levels for metallic components under complex, ... more The prediction of fatigue life or allowable stress levels for metallic components under complex, multiaxial stress states is a challenging aspect in design. While equivalent-stress approaches often work reasonably well for simple proportional load paths, the analysis of non-proportional load paths brings forth additional complexities, such as the identification of cycles and the definition of mean stresses. Critical plane approaches, in which the orientation of the plane on which the crack will nucleate is taken into consideration, have shown better success in correlating experimental results under a wide variety of load paths. However, while the interpretation of the stress terms in a critical plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is non-proportional. In this paper, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical plane...
International Journal of Fatigue, 2005
A new approach, which uses the Findley critical plane damage parameter along with the stress grad... more A new approach, which uses the Findley critical plane damage parameter along with the stress gradient at the notch, was developed for predicting notched HCF life. The proposed approach and methodology for HCF notch analysis accounts for: (i) the multiaxial stress state at the notch, (ii) the notch size effect, and (iii) the effect of fatigue stress ratio. Two fatigue
The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer mat... more The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer matrix composites is an enabling technology that will help reduce vehicle weight and increase payload capacity of future aircraft and spacecraft. A challenge in designing these tanks is selecting and characterizing composite material systems that show strong resistance to microcrack formation under cyclic mechanical loads caused by repeated fill and drain cycles of the tank. This paper studies the growth of damage as a function of mechanical cyclic load for three novel, microcrack-resistant materials that were purpose-designed by Composite Technology Development, Inc. (CTD) for linerless composite tank applications. Cross-ply [0/90]s composite laminates were subjected to uniaxial cyclic loading at room temperature. The development of microcracks in the transverse plies was monitored as a function of cycles for different target strain levels. The experimental results show significant differe...
The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer mat... more The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer matrix composites is an enabling technology that will help reduce vehicle weight and increase payload capacity of future aircraft and spacecraft. A challenge in designing these tanks is selecting and characterizing composite material systems that show strong resistance to microcrack formation under cyclic mechanical loads caused by repeated fill and drain cycles of the tank. This paper studies the growth of damage as a function of mechanical cyclic load for three novel, microcrack-resistant materials that were purpose-designed by Composite Technology Development, Inc. (CTD) for linerless composite tank applications. Cross-ply [0/90]s composite laminates were subjected to uniaxial cyclic loading at room temperature. The development of microcracks in the transverse plies was monitored as a function of cycles for different target strain levels. The experimental results show significant differe...
Journal of Engineering Materials and Technology, 2008
The prediction of fatigue life for metallic components subjected to complex multiaxial stress sta... more The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical-plane methodology. Uniaxial and multiaxial fatigue data from Ti–6Al–4V and three other alloys, namely, Rene’104, Rene’88DT, and Direct Age 718, are used as the basis for the evaluation. The experimental fatigue data include axial, torsional, proportional, and a variety of nonproportional tension/torsion load paths. Specific attention is given to the effects of torsional mean stresses, the definition of the critical plane, and the interpretation of normal stress terms on the critical plane within nonproportional load paths. A new modification to a critical-plane parameter is presented, which provides a good correlation of experimental fatigue data.
... AIR FORCE RESEARCH LABORATORY AIR FORCE MATERIEL COMMAND WRIGHT-PATTERSON AIR FORCE BASE, OH ... more ... AIR FORCE RESEARCH LABORATORY AIR FORCE MATERIEL COMMAND WRIGHT-PATTERSON AIR FORCE BASE, OH 45433-7750 Page 2. NOTICE ... _____ RYAN J. MORRISSEY ROLLIE DUTTON Program Manager ...
Many critical engineering components are routinely subjected to cyclic multiaxial stress states, ... more Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Initial efforts by the authors involved the identification of suitable multiaxial damage parameters for a Ti-6Al-4V titanium alloy utilizing smooth samples. As with uniaxial loading, the extension of the multiaxial data to a notched geometry poses challenges. Utilizing the
A study of delamination damage growth in a fiberglass/epoxy laminate composite subjected to low v... more A study of delamination damage growth in a fiberglass/epoxy laminate composite subjected to low velocity impacts, moisture and low temperature thermal cycling was undertaken. The research addresses two different ply configurations (0/90/0/90/02)s & (02/902/02)s, three impact energies 5J, 10J, & 15J and two impact masses 7.25 kg & 12.25 kg, at both dry and wet service conditions. Test specimens were
Past research has shown there is a nonlinear interaction effect between LCF (high damage) and HCF... more Past research has shown there is a nonlinear interaction effect between LCF (high damage) and HCF (low damage) cycles in many engineering materials. This effect has been observed within uniaxial loadings, but is often more pronounced under multiaxial loadings, particularly when the loading is non-proportional. This is an area of concern in the development of fatigue damage assessment methods for
Several multiaxial (tension/torsion) mission-history tests were conducted on smooth bars of Ti-6A... more Several multiaxial (tension/torsion) mission-history tests were conducted on smooth bars of Ti-6Al-4V. The mission histories were constructed of a single out-of-phase LCF cycle (in the form of a "box" or "check" path) coupled with 5 to 50 small HCF cycles. The stress paths and magnitudes for the LCF and HCF cycles were chosen to produce significantly different damage levels on
The authors have previously evaluated over twenty fatigue damage parameters for application to ti... more The authors have previously evaluated over twenty fatigue damage parameters for application to titanium alloys (Ti-6Al-4V) subjected to constant amplitude loadings. Equivalent stress based parameters and critical plane parameters were considered for both proportional and non-proportional multiaxial load paths. The evaluations were based on the ability of the models to correlate tension/torsion fatigue data to a uniaxial baseline. Only a
SAE Technical Paper Series, 1993
Abstract The objective of this research was to determine the feasibility of applying strain based... more Abstract The objective of this research was to determine the feasibility of applying strain based fatigue life calculation models, which are commonly used for metals, to smooth SRIM polymer matrix composite axial specimens subjected to variable amplitude loading. A ...
47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference<BR> 14th AIAA/ASME/AHS Adaptive Structures Conference<BR> 7th, 2006
Journal of Sandwich Structures and Materials, 2005
Composite sandwich panels constructed from glass-fiber-reinforced facesheets surrounding both foa... more Composite sandwich panels constructed from glass-fiber-reinforced facesheets surrounding both foam-filled and nonfilled honeycomb cores are impacted using a drop-weight impactor at three energy levels and three temperatures. The effects of core material, temperature, and impact velocity on the absorbed energy, peak impact force, and damage mechanisms were studied. The foam-filled samples were subsequently subjected to four-point bend tests to investigate the effect of impact velocity and temperature on the damage tolerance and residual strength of the composites. It was found that the temperature can have a significant effect on the energy absorbed and maximum force encountered during impact, although the effect of the impact temperature on the residual bending stiffness and strength of the composites was mixed. In addition, the nature of the core material greatly influenced the damage mechanisms and impact force transfer in the honeycomb sandwich composites.
Journal of Engineering Materials and Technology, 2002
Many critical engineering components are routinely subjected to cyclic multiaxial stress states, ... more Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Existing multiaxial fatigue models are examined to determine their suitability at estimating fatigue damage in Ti-6Al-4V under complex, multiaxial loading, with an emphasis on long-life conditions. Both proportional and non-proportional strain-controlled tension/torsion experiments were conducted on solid specimens. Several multiaxial fatigue damage parameters are evaluated based on their ability to correlate the biaxial fatigue data and uniaxial fatigue data with tensile mean stresses (R>−1) to a fully-reversed (R=−1) uniaxial baseline. Both equivalent stress-based models and critical plane approaches are evaluated. Only one equivalent stress model and two critical plane models showed promise for the range of loadings and material considered.
Journal of Engineering Materials and Technology, 2008
The prediction of fatigue life for metallic components subjected to complex multiaxial stress sta... more The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examinati...
Journal of Composite Materials, 1999
Page 1. Journal of Composite Materials http://jcm.sagepub.com/ A Finite Element Model for Predict... more Page 1. Journal of Composite Materials http://jcm.sagepub.com/ A Finite Element Model for Predicting Time-Dependent Deformations and Damage Accumulation in Laminated Composite Bolted Joints Alan R. Kallmeyer and ...
Notched Izod impact tests were conducted on wet and dry specimens of a pultruded, glass fiber-rei... more Notched Izod impact tests were conducted on wet and dry specimens of a pultruded, glass fiber-reinforced polymer compos-ite after thermal cycling between 25 and −50ºC. Specimens were impacted following the application of 50, 150, and 300 thermal cycles. The results indicate that moisture initially had a benefi-cial effect on the notch toughness, probably due to a reduction in residual stresses from matrix swelling. After 300 thermal cycles, the beneficial effect of moisture was negated, likely due to an increase in damage from freeze/thaw expansion of the water, and a reduction in the overall moisture state in the composite. Fur-ther research is needed to quantify the damage accumulation during low-temperature thermal cycling.
The prediction of fatigue life or allowable stress levels for metallic components under complex, ... more The prediction of fatigue life or allowable stress levels for metallic components under complex, multiaxial stress states is a challenging aspect in design. While equivalent-stress approaches often work reasonably well for simple proportional load paths, the analysis of non-proportional load paths brings forth additional complexities, such as the identification of cycles and the definition of mean stresses. Critical plane approaches, in which the orientation of the plane on which the crack will nucleate is taken into consideration, have shown better success in correlating experimental results under a wide variety of load paths. However, while the interpretation of the stress terms in a critical plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is non-proportional. In this paper, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical plane...
International Journal of Fatigue, 2005
A new approach, which uses the Findley critical plane damage parameter along with the stress grad... more A new approach, which uses the Findley critical plane damage parameter along with the stress gradient at the notch, was developed for predicting notched HCF life. The proposed approach and methodology for HCF notch analysis accounts for: (i) the multiaxial stress state at the notch, (ii) the notch size effect, and (iii) the effect of fatigue stress ratio. Two fatigue
The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer mat... more The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer matrix composites is an enabling technology that will help reduce vehicle weight and increase payload capacity of future aircraft and spacecraft. A challenge in designing these tanks is selecting and characterizing composite material systems that show strong resistance to microcrack formation under cyclic mechanical loads caused by repeated fill and drain cycles of the tank. This paper studies the growth of damage as a function of mechanical cyclic load for three novel, microcrack-resistant materials that were purpose-designed by Composite Technology Development, Inc. (CTD) for linerless composite tank applications. Cross-ply [0/90]s composite laminates were subjected to uniaxial cyclic loading at room temperature. The development of microcracks in the transverse plies was monitored as a function of cycles for different target strain levels. The experimental results show significant differe...
The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer mat... more The development of linerless composite tanks fabricated with carbon fiber reinforced, polymer matrix composites is an enabling technology that will help reduce vehicle weight and increase payload capacity of future aircraft and spacecraft. A challenge in designing these tanks is selecting and characterizing composite material systems that show strong resistance to microcrack formation under cyclic mechanical loads caused by repeated fill and drain cycles of the tank. This paper studies the growth of damage as a function of mechanical cyclic load for three novel, microcrack-resistant materials that were purpose-designed by Composite Technology Development, Inc. (CTD) for linerless composite tank applications. Cross-ply [0/90]s composite laminates were subjected to uniaxial cyclic loading at room temperature. The development of microcracks in the transverse plies was monitored as a function of cycles for different target strain levels. The experimental results show significant differe...
Journal of Engineering Materials and Technology, 2008
The prediction of fatigue life for metallic components subjected to complex multiaxial stress sta... more The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examination of the variables responsible for crack nucleation is presented in the context of the critical-plane methodology. Uniaxial and multiaxial fatigue data from Ti–6Al–4V and three other alloys, namely, Rene’104, Rene’88DT, and Direct Age 718, are used as the basis for the evaluation. The experimental fatigue data include axial, torsional, proportional, and a variety of nonproportional tension/torsion load paths. Specific attention is given to the effects of torsional mean stresses, the definition of the critical plane, and the interpretation of normal stress terms on the critical plane within nonproportional load paths. A new modification to a critical-plane parameter is presented, which provides a good correlation of experimental fatigue data.
... AIR FORCE RESEARCH LABORATORY AIR FORCE MATERIEL COMMAND WRIGHT-PATTERSON AIR FORCE BASE, OH ... more ... AIR FORCE RESEARCH LABORATORY AIR FORCE MATERIEL COMMAND WRIGHT-PATTERSON AIR FORCE BASE, OH 45433-7750 Page 2. NOTICE ... _____ RYAN J. MORRISSEY ROLLIE DUTTON Program Manager ...
Many critical engineering components are routinely subjected to cyclic multiaxial stress states, ... more Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Initial efforts by the authors involved the identification of suitable multiaxial damage parameters for a Ti-6Al-4V titanium alloy utilizing smooth samples. As with uniaxial loading, the extension of the multiaxial data to a notched geometry poses challenges. Utilizing the
A study of delamination damage growth in a fiberglass/epoxy laminate composite subjected to low v... more A study of delamination damage growth in a fiberglass/epoxy laminate composite subjected to low velocity impacts, moisture and low temperature thermal cycling was undertaken. The research addresses two different ply configurations (0/90/0/90/02)s & (02/902/02)s, three impact energies 5J, 10J, & 15J and two impact masses 7.25 kg & 12.25 kg, at both dry and wet service conditions. Test specimens were
Past research has shown there is a nonlinear interaction effect between LCF (high damage) and HCF... more Past research has shown there is a nonlinear interaction effect between LCF (high damage) and HCF (low damage) cycles in many engineering materials. This effect has been observed within uniaxial loadings, but is often more pronounced under multiaxial loadings, particularly when the loading is non-proportional. This is an area of concern in the development of fatigue damage assessment methods for
Several multiaxial (tension/torsion) mission-history tests were conducted on smooth bars of Ti-6A... more Several multiaxial (tension/torsion) mission-history tests were conducted on smooth bars of Ti-6Al-4V. The mission histories were constructed of a single out-of-phase LCF cycle (in the form of a "box" or "check" path) coupled with 5 to 50 small HCF cycles. The stress paths and magnitudes for the LCF and HCF cycles were chosen to produce significantly different damage levels on
The authors have previously evaluated over twenty fatigue damage parameters for application to ti... more The authors have previously evaluated over twenty fatigue damage parameters for application to titanium alloys (Ti-6Al-4V) subjected to constant amplitude loadings. Equivalent stress based parameters and critical plane parameters were considered for both proportional and non-proportional multiaxial load paths. The evaluations were based on the ability of the models to correlate tension/torsion fatigue data to a uniaxial baseline. Only a
SAE Technical Paper Series, 1993
Abstract The objective of this research was to determine the feasibility of applying strain based... more Abstract The objective of this research was to determine the feasibility of applying strain based fatigue life calculation models, which are commonly used for metals, to smooth SRIM polymer matrix composite axial specimens subjected to variable amplitude loading. A ...
47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference<BR> 14th AIAA/ASME/AHS Adaptive Structures Conference<BR> 7th, 2006
Journal of Sandwich Structures and Materials, 2005
Composite sandwich panels constructed from glass-fiber-reinforced facesheets surrounding both foa... more Composite sandwich panels constructed from glass-fiber-reinforced facesheets surrounding both foam-filled and nonfilled honeycomb cores are impacted using a drop-weight impactor at three energy levels and three temperatures. The effects of core material, temperature, and impact velocity on the absorbed energy, peak impact force, and damage mechanisms were studied. The foam-filled samples were subsequently subjected to four-point bend tests to investigate the effect of impact velocity and temperature on the damage tolerance and residual strength of the composites. It was found that the temperature can have a significant effect on the energy absorbed and maximum force encountered during impact, although the effect of the impact temperature on the residual bending stiffness and strength of the composites was mixed. In addition, the nature of the core material greatly influenced the damage mechanisms and impact force transfer in the honeycomb sandwich composites.
Journal of Engineering Materials and Technology, 2002
Many critical engineering components are routinely subjected to cyclic multiaxial stress states, ... more Many critical engineering components are routinely subjected to cyclic multiaxial stress states, which may include non-proportional loading and multidimensional mean stresses. Existing multiaxial fatigue models are examined to determine their suitability at estimating fatigue damage in Ti-6Al-4V under complex, multiaxial loading, with an emphasis on long-life conditions. Both proportional and non-proportional strain-controlled tension/torsion experiments were conducted on solid specimens. Several multiaxial fatigue damage parameters are evaluated based on their ability to correlate the biaxial fatigue data and uniaxial fatigue data with tensile mean stresses (R>−1) to a fully-reversed (R=−1) uniaxial baseline. Both equivalent stress-based models and critical plane approaches are evaluated. Only one equivalent stress model and two critical plane models showed promise for the range of loadings and material considered.
Journal of Engineering Materials and Technology, 2008
The prediction of fatigue life for metallic components subjected to complex multiaxial stress sta... more The prediction of fatigue life for metallic components subjected to complex multiaxial stress states is a challenging aspect in design. Equivalent-stress approaches often work reasonably well for uniaxial and proportional load paths; however, the analysis of nonproportional load paths brings forth complexities, such as the identification of cycles, definition of mean stresses, and phase shifts, that the equivalent-stress approaches have difficulties in modeling. Shear-stress based critical-plane approaches, which consider the orientation of the plane on which the crack is assumed to nucleate, have shown better success in correlating experimental results for a broader variety of load paths than equivalent-stress models. However, while the interpretation of the ancillary stress terms in a critical-plane parameter is generally straightforward within proportional loadings, there is often ambiguity in the definition when the loading is nonproportional. In this study, a thorough examinati...
Journal of Composite Materials, 1999
Page 1. Journal of Composite Materials http://jcm.sagepub.com/ A Finite Element Model for Predict... more Page 1. Journal of Composite Materials http://jcm.sagepub.com/ A Finite Element Model for Predicting Time-Dependent Deformations and Damage Accumulation in Laminated Composite Bolted Joints Alan R. Kallmeyer and ...