Bazle A. Gama
University of Delaware
Composite numberEngineeringCeramicFinite element methodStrain rateComposite materialEpoxyCompression (physics)Materials scienceBallistic impactPlain weaveMetal foamProjectileMechanicsStructural engineeringDelaminationArmourSplit-Hopkinson pressure barStress (mechanics)Shear (geology)
46Publications
18H-index
1,923Citations
Publications 43
Newest
#1Bazle A. Gama (UD: University of Delaware)H-Index: 18
#2Sergey L. Lopatnikov (UD: University of Delaware)H-Index: 15
Last. John W. Gillespie (UD: University of Delaware)H-Index: 70
view all 3 authors...
Progressive collapse behavior of closed cell aluminum foam under multiple-impact loading is presented. A direct impact Hopkinson pressure bar set up is developed to impact aluminum foam cylinders with a striker bar at a constant impact velocity. The total length of the specimen before and after impact is measured. The incident bar response is recorded, and average stress in the specimen is calculated. The incremental plastic strain and maximum strain rate is calculated from basic test parameters...
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#1Bazle A. Gama (UD: University of Delaware)H-Index: 18
#2John W. Gillespie (UD: University of Delaware)H-Index: 70
A new experimental method is developed to determine the fiber crush strength (SFC) and fiber shear strength (SFS) of composite materials following a punch shear test methodology. The material parameters SFC and SFS are used to model the damage behavior of thick-section composites as described in the LS-Dyna material model MAT_COMPOSITE_DMG_MSC, aka MAT162. The quasi-static experimental methodology is further extended to investigate the rate effect on SFS using a Hopkinson bar direct impact punch...
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#1John W. Gillespie (UD: University of Delaware)H-Index: 70
#2Bazle A. Gama (UD: University of Delaware)H-Index: 18
Last. J.R. Xiao (UD: University of Delaware)H-Index: 21
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Abstract In this study a test methodology for measuring interlaminar shear strength of composites under both quasi-static and high strain rate loadings is developed. The test methodology is also able to study the effect of the Coulomb friction and the influence of interlaminar compressive stress acting on the failure plane. The material properties generated are used to evaluate various quasi-static and strain rate dependent failure criteria. This is accomplished by testing out-of-plane off-axis ...
38 CitationsSource
#1S. Mahdi (UD: University of Delaware)H-Index: 3
#2Bazle A. Gama (UD: University of Delaware)H-Index: 18
Last. John W. Gillespie (UD: University of Delaware)H-Index: 70
view all 4 authors...
Composite structural armor (CSA) is a multifunctional material that provides ballistic protection, stiffness, and strength at minimum weight. It consists of a multilayered architecture of polymer composites, rubber and ceramic tiles, stacked in a precise manner to obtain optimal performance. During its lifetime, CSA will experience manufacturing defects and be subjected from low to high velocity impact threats that will reduce the performance of the structure. The ability to repair a CSA is cons...
3 CitationsSource
#1J.R. Xiao (UD: University of Delaware)H-Index: 21
#2Bazle A. Gama (UD: University of Delaware)H-Index: 18
Last. John W. Gillespie (UD: University of Delaware)H-Index: 70
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Abstract An analytical molecular structural mechanics model for the prediction of mechanical properties of defect-free carbon nanotubes is developed by incorporating the modified Morse potential with an analytical molecular structural model. The developed model is capable of predicting Young’s moduli, Poisson’s ratios and stress–strain relationships of carbon nanotubes under tension and torsion loading conditions. Results on the mechanical properties of single-walled carbon nanotubes show that Y...
262 CitationsSource
#1J.R. Xiao (UD: University of Delaware)H-Index: 21
#2Bazle A. Gama (UD: University of Delaware)H-Index: 18
Last. Edward J. Kansa (UC Davis: University of California, Davis)H-Index: 2
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A subdomain variational inequality and its meshless linear complementary formulation are developed in the present paper for solving two-dimensional contact problems. The subdomain variational inequality will be defined in detail. The meshless method is based on a local weighted residual method with the Heaviside step function as the weighting function over a local subdomain and radial basis functions as trial functions for interpolation. Three different radial basis functions (RBFs), i.e. Multiq...
28 CitationsSource
#1Bazle A. GamaH-Index: 18
#2S. M. Waliul IslamH-Index: 1
Last. Chris P. R. HoppelH-Index: 2
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19 Citations
#1Alper TaşdemirciH-Index: 17
#2Ian W. HallH-Index: 21
Last. Mustafa GüdenH-Index: 26
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Abstract : Multilayer materials consisting of ceramic and glass/epoxy with a rubber interlayer have been subjected to a high strain rate compression using a split-Hopkinson Pressure Bar (SHPB). The feasibility of modeling stress wave propagation in complex multilayer materials has been demonstrated. It has been shown that the effects of lateral confinement of a normally low-modulus interlayer material can significantly affect the response to wave propagation. Numerical modeling clearly shows tha...
1 CitationsSource
#1Bazle A. Gama (UD: University of Delaware)H-Index: 18
#2Stephane Mahdi (UD: University of Delaware)H-Index: 1
Last. John W. Gillespie (UD: University of Delaware)H-Index: 70
view all 5 authors...
Abstract : One of the many challenges facing weapon developers is the requirement for a highly lethal, lightweight, and compact large caliber gun system. One concept recently investigated by the U.S. Army is that of a swing-chamber gun, necessitating the use of telescoped ammunition. Such ammunition not only reduces the volume available for the propellant change, but also places severe geometric constraints on both the distribution of the propellant and the location and functionality of the igni...
3 CitationsSource
#1Libo RenH-Index: 2
#2Mike LarsonH-Index: 1
Last. John W. GillespieH-Index: 70
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Abstract : It is well known that harmonic waves with higher frequencies travel slower than those with lower frequencies and that they are known as wave dispersion in finite diameter rods. From the frequency equation, the phase speed can be determined if the wavelength is known. A dispersion correction methodology uses the frequency equation to disperse a waveform to a specific location of interest. Dispersion correction methodologies are generally used in split-Hopkinson pressure bar (SHPB) tech...
8 CitationsSource