Numerical modeling of effect of polyurea on response of steel plates to impulsive loads in direct pressure-pulse experiments

Amini, M.R.; Simon, Jaan‐Willem; Nemat‐Nasser, Sia

doi:10.1016/j.mechmat.2009.09.009

Cited by 103 publications

(47 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18(a) and 19(a). This phenomenon is directly related to the location of the polyurea layer and has been described by Amini et al [13][14][15][16]. Polyurea is a highly pressure sensitive elastomer with its shear and bulk stiffness increasing remarkably with increasing pressure [8].…”

Section: Energy Redistribution Behaviormentioning

confidence: 77%

“…Their results suggest that separating the composite facesheet from the foam core by a thin interlayer of polyurea can be very beneficial in comparison to the conventional sandwich plate design. Amini et al [13][14][15][16] experimentally and numerically studied the dynamic response of circular monolithic steel and steel-polyurea bilayer plates to impulsive loads. More importantly they focused on the significance of the relative position of the polyurea layer with respect to the loading direction.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Blast Mitigation in a Sandwich Composite Using Graded Core and Polyurea Interlayer

et al. 2011

View full text Add to dashboard Cite

The dynamic behavior of two types of sandwich composites made of E-Glass Vinyl-Ester (EVE) facesheets and Corecell™ A-series foam with a polyurea interlayer was studied using a shock tube apparatus. The materials, as well as the core layer arrangements, were identical, with the only difference arising in the location of the polyurea interlayer. The foam core itself was layered with monotonically increasing wave impedance of the core layers, with the lowest wave impedance facing the shock loading. For configuration 1, the polyurea interlayer was placed behind the front facesheet, in front of the foam core, while in configuration 2 it was placed behind the foam core, in front of the back facesheet. A high-speed side-view camera, along with a high-speed back-view 3-D Digital Image Correlation (DIC) system, was utilized to capture the real time deformation process as well as mechanisms of failure. Post mortem analysis was also carried out to evaluate the overall blast performance of these two configurations. The results indicated that applying polyurea behind the foam core and in front of the back facesheet will reduce the back face deflection, particle velocity, and in-plane strain, thus improving the overall blast performance and maintaining structural integrity.

show abstract

Section: Energy Redistribution Behaviormentioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Blast Mitigation in a Sandwich Composite Using Graded Core and Polyurea Interlayer

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Strain rate can have a significant influence on the ultimate tensile and shear stresses (Huang et al 2009, Amini et al 2010. Likewise, elevated temperature may also give rise to material instability; in particular, under dynamic loading of high dynamic energy content (Deng and Nemat-Nasser 1992).…”

Section: Stress Triaxiality Strain Rate and Temperature Effectsmentioning

confidence: 99%

Dynamic delamination in laminated fiber reinforced composites: A continuum damage mechanics approach

Shojaei

Tan

et al. 2015

International Journal of Solids and Structures

View full text Add to dashboard Cite

Delamination causes a significant reduction in the load carrying capacity of Fiber Reinforced Polymer (FRP) composites, which is a major concern to the aerospace and automotive industries. High performance FRPs are often subjected to dynamic loadings of different energy densities in their service life when strain rate, stress triaxiality, temperature, and mode of fracture can have a significant knock-down effect on the interfacial strength of plies in a laminate. This paper develops a predictive tool, in a Continuum Damage Mechanics (CDM) framework, to assess delamination damage in FRPs under dynamic loading; the model takes into account the effects of dynamic energy density, mixed-mode fractures and temperature.The CDM model is formulated based on the Fracture Mechanics (FM) of decohesion and an advantage of the proposed model is that nearly all of the material parameters can be obtained directly through calibration to experimental data rather than numerical curve fitting of simulation results. The developed scheme is coded into a commercial FEA package (ABAQUS) through user-defined subroutines and the fidelity of the model is assessed by comparison with existing experimental data in the literature. The validated model is used to investigate delamination damage in a laminated FRP subject to projectile impact loading, where it will be shown that the extent of delamination damage through the thickness of the FRP structure is dependent upon different wave propagation scenarios. The proposed model provides a design platform for damage assessment caused by dynamic delamination and may be a useful tool for designing FRP composites with a greater impact tolerance.

show abstract

“…10. This imposed deformation is based on the results of a full-scale simulation of the plate in the direction of the impulse in the experiment, as reported in Amini et al (2010b). The boundary and initial conditions are imposed on the model as if the plate is loaded on its upper surface (Fig.…”

Section: Finite-element Setupmentioning

confidence: 99%

Micromechanisms of ductile fracturing of DH-36 steel plates under impulsive loads and influence of polyurea reinforcing

Amini

Nemat‐Nasser

2010

Int J Fract

Self Cite

View full text Add to dashboard Cite

Micromechanisms of ductile fracturing of DH-36 steel plates subjected to blast-induced pressure loads are studied experimentally using specially designed dynamic testing facilities. The sample geometry is such that it undergoes controllable fracturing, generally initiated near its center and grows first circumferentially and then radially. Selected fractured samples are sectioned normal to the fracture surfaces, at various intervals along the length of the fracture which extends into the necked and finally to the uniformlydeformed material. The thickness profile of the sample at each cross section is analyzed using optical and scanning electron microscopy. In this manner, we have been able to examine the microstructural evolution that has taken place, from necking inception to fracture initiation and growth, leading to a better understanding of the underpinning mechanisms of the fracturing of this material. The observed ductile fracture involves void nucleation, and void growth and coalescence, creating dimpled fracture surfaces. The examination of the microstructure of the deformed steel samples also revealed that the microstructure does not change M. R. Amini Omnicell Inc., 1201 Charleston Road, Mountain View, CA 94093, USA e-mail: mr_amini_2000@yahoo.com S. Nemat-Nasser (B) Center of Excellence for Advanced Materials, Department of Mechanical and Aerospace Engineering, University of California, La Jolla, San Diego, CA 92093-0416, USA e-mail: sia@ucsd.edu significantly during the deformation and that there are no shearbands developing in and around the fracture zones. Based on the observed micro-scale deformation, a finite-element model was developed to further study the fracturing process, using a physics-based and experimentally-supported temperature-and rate-sensitive constitutive model for DH-36 steel. The finiteelement model was capable of predicting the fracture process of the steel plates rather well. Additional finiteelement simulations are performed to investigate the effect of the polyurea coating on the fracturing and fracture resistance of the plates. These also correlated well with the experimental results.

show abstract

Numerical modeling of effect of polyurea on response of steel plates to impulsive loads in direct pressure-pulse experiments

Cited by 103 publications

References 11 publications

Blast Mitigation in a Sandwich Composite Using Graded Core and Polyurea Interlayer

Blast Mitigation in a Sandwich Composite Using Graded Core and Polyurea Interlayer

Dynamic delamination in laminated fiber reinforced composites: A continuum damage mechanics approach

Micromechanisms of ductile fracturing of DH-36 steel plates under impulsive loads and influence of polyurea reinforcing

Contact Info

Product

Resources

About