Repeated localized impulsive loading on monolithic and multi-layered metallic plates

Rezasefat, Mohammad; Mostofi, Tohid Mirzababaie; Ozbakkaloglu, Togay

doi:10.1016/j.tws.2019.106332

Cited by 31 publications

(8 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The damage parameter D was defined aswhere Δε¯pl and ε¯fpl were the increment of equivalent plastic strain and the strain at fracture, respectively. Once the plastic strain accumulated in all incremental steps of an element reached the fracture strain, the element was directly removed (without stiffness degradation 31 ). Further, ε¯fpl was given bywhere σ∗ was the stress triaxiality, and D 1 – D 5 were the failure parameters.…”

Section: Numerical Simulationsmentioning

confidence: 99%

Multiple ballistic impacts of thin metallic plates: Numerical simulation

Qiang

Zhang

Zhao

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

The ballistic performance of protective structures under multiple projectile impacts attracts increasing attention due to its practical importance, and existing studies were seldomly devoted to exploring how the structure would deform and fail when subjected to such loads. This study aimed to characterize the multi-hit ballistic resistance of fully-clamped thin plates made of 304 stainless steel using finite element method, with the equivalent plastic strain employed to define material damage and failure/fracture. The numerical model was validated against existing experimental results of double impacts at the same location, with good agreement achieved. The model was subsequently employed to quantify the effects of impact position, interval time between successive hits, projectile nose shape (e.g., spherical, flat and conical), and boundary condition of target plate on ballistic limit and deformation/failure modes. Further, ballistic limit boundaries were constructed for both double and triple impacts of projectiles. Obtained results are helpful for designing high-performance protective structures against multiple projectile impacts.

show abstract

Section: Numerical Simulationsmentioning

confidence: 99%

Multiple ballistic impacts of thin metallic plates: Numerical simulation

Qiang

Zhang

Zhao

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

show abstract

“…Þ, while the equivalent plastic strain e pl reaches the critical value of the equivalent plastic failure strain. 34 In this situation, the equivalent plastic failure strain value e pl f severely relies on the element characteristic length L due to strain localization and it cannot be employed as a material parameter to define the damage evolution law. Therefore, the damage evolution law is defined by the following relationship in terms of the equivalent plastic displacement u pl34 u pl ¼ L e pl À e pl D (5) where L depends on the element geometry and it is considered as the cube root of the integration point volume in the present study.…”

Section: Materials Modelmentioning

confidence: 99%

“…At any given time during the analysis of a damaged element, the true degraded stress tensor r is expressed in terms of the effective stress r as follows 34 r…”

Section: Materials Modelmentioning

confidence: 99%

See 1 more Smart Citation

An experimental and numerical investigation on impact spot welding of metallic plates using gas mixture detonation technique

Hosseinzadeh

Babaei

Mostofi³

2020

Proceedings of the Institution of Mechanical Engineers, Part L:

Self Cite

View full text Add to dashboard Cite

In this paper, the impact spot welding of metallic plates was investigated both experimentally and numerically using a single-stage gas mixture detonation apparatus. The impact spot welding process was carried out on aluminum alloy and steel materials using rigid steel projectiles. In this process, the mixture of oxygen and acetylene was detonated in a combustion chamber to launch the projectile. The masses of flat- and spherical-nosed projectiles were 270 and 230 g, respectively. The impact velocity was measured in all experiments. The cross-sections of the weld spots were inspired by a scanning electron microscope to assess the quality of welding. For several experiments, wavy interfaces were observed showing there is a good bonding. For numerical simulation of the process, Abaqus/Explicit software was used and the deformation and failure mechanisms of impact spot-welded specimens were further investigated. The Johnson–Cook thermoplasticity model along with its failure model was utilized to predict the behavior of metallic materials. The numerical simulation results were in good agreement with those obtained from experiments in terms of the deformation mode and failure pattern. The propagation of the wave on the surface of the flyer plate was further studied. The results showed that the stress waves start from the center and propagate to the corners of the plate. To numerically evaluate the welding quality, two parameters of the shear stress at the collision point as well as the equivalent plastic strain for the flyer and target plates were obtained in the numerical simulation. The numerical results showed opposite directions of shear stress for flyer and base plates at the contact point, which can be used as proof for good bonding. Besides, the magnitudes of the equivalent plastic strain for both flyer and base plates were higher than those reported values in the open literature that confirms successful welding.

show abstract

“…Due to explosives or impact loading, these structures respond in a manner that is complex and nonlinear in nature 1 , 2 . Thus extensive experimental, analytical and numerical investigations have been carried out to study the mitigative effect of the protective structures under extreme loads 3 – 8 .The rapid advancement of computers has motivated various analysis techniques capable to model the complex dynamic response to a high level of accuracy 9 – 11 .…”

Section: Introductionmentioning

confidence: 99%

Flexure and shear response of an impulsively loaded rigid-plastic beam by enhanced linear complementarity approach

Khan

Tariq

Ullah

et al. 2022

Sci Rep

View full text Add to dashboard Cite

The linear complementarity approach has been utilized as a systematic and unified numerical process for determining the response of a rigid-plastic structure subjected to impulsive loading. However, the popular Lemke Algorithm for solving linear complementarity problems (LCP) encounters numerical instability issues whilst tracing the response of structures under extreme dynamic loading. This paper presents an efficient LCP approach with an enhanced initiation subroutine for resolving the numerical difficulties of the solver. The numerical response of the impulsively loaded structures is affected by the initial velocity profile, which if not found correctly can undermine the overall response. In the current study, the initial velocity profile is determined by a Linear Programming (LP) subroutine minimizing the energy function. An example of a uniform impulsively loaded simply supported beam is adduced to show the validity and accuracy of the proposed approach. The beam is approximated with bending hinges having infinite resistance to shear. Comparison of the numerical results to the available closed-form solution confirms the excellent performance of the approach. However, a subsequent investigation into a beam having the same support conditions and the applied loading, but with bending and shear deformation, results in numerical instability despite optimizing the initial velocity profile. Thus a more generic description of kinetics and kinematics is proposed that can further enhance the numerical efficiency of the LCP formulation. The ensuing numerical results are compared with the available close form solution to assess the accuracy and efficiency of the developed approach.

show abstract

Repeated localized impulsive loading on monolithic and multi-layered metallic plates

Cited by 31 publications

References 49 publications

Multiple ballistic impacts of thin metallic plates: Numerical simulation

Multiple ballistic impacts of thin metallic plates: Numerical simulation

An experimental and numerical investigation on impact spot welding of metallic plates using gas mixture detonation technique

Flexure and shear response of an impulsively loaded rigid-plastic beam by enhanced linear complementarity approach

Contact Info

Product

Resources

About