Experimental, theoretical, and numerical studies on the response of square plates subjected to blast loading

2011 ◽  
Vol 46 (8) ◽  
pp. 805-816 ◽  
Author(s):  
K H Safari ◽  
J Zamani ◽  
S M R Khalili ◽  
S Jalili
Keyword(s):  
Blast Wave ◽  
Failure Modes ◽  
Scaling Law ◽  
Blast Loading ◽  
Material Failure ◽  
Perfectly Plastic ◽  
Numerical Studies ◽  
Fluid Solid Interaction ◽  
Interaction Problem ◽  
Dynamic Plasticity

This article presents the results of experimental and analytical studies on the response of steel and aluminium square plates with different thicknesses subjected to blast loading. Based on the blast wave details and the scaling law for explosions, a method of determining the blast load is proposed in which ballistic pendulums do not need to be utilized for obtaining the blast wave impulses. The loads applied to the plates are assumed to be the quasi-exponential pressure pulses, which are the same as the explosion overpressures. The theoretical solutions are presented using a rigid, perfectly plastic idealization and are exact within the context of dynamic plasticity. The dynamic energy imparted to structures can cause material failure. The presented investigation considers such a failure for fully clamped plates subjected to a blast loading idealized as an initial velocity distributed uniformly throughout the area. The predicted deflections and general failure modes of the plates are presented and compared with experimental results. Moreover, a numerical simulation is carried out by modelling an FSI (fluid–solid interaction) problem. Results are compared with each other and a better agreement between numerical results with experimental ones is observed.

Revisiting the generalized scaling law for adhesion: role of compliance and extension to progressive failure

Soft Matter ◽  
2017 ◽  
Vol 13 (41) ◽  
pp. 7529-7536 ◽  
Author(s):  
Ahmad R. Mojdehi ◽  
Douglas P. Holmes ◽  
David A. Dillard
Keyword(s):  
Fracture Mechanics ◽  
Failure Modes ◽  
Progressive Failure ◽  
Scaling Law ◽  
Load Train ◽  
Adhesion Role

The generalized scaling law for adhesion is revisited, based on the classical fracture mechanics approach, leading to a revised scaling law that accounts for the role of load train compliance and extends to progressive failure modes.

Materials Failure Logic Models—A Procedure for Systematic Identification of Material Failure Modes in Mechanical Components

1982 ◽  
Vol 104 (3) ◽  
pp. 626-634 ◽  
Author(s):  
D. L. Marriott ◽  
N. R. Miller
Keyword(s):  
Failure Modes ◽  
Planning Process ◽  
Service Failure ◽  
Failure Mechanisms ◽  
Material Failure ◽  
Cad System ◽  
Logic Models ◽  
Identification Technique ◽  
Mechanical Components ◽  
Systematic Identification

This paper addresses the problem of improvement of mechanical component reliability by the systematic identification of material failure mechanisms. Experience shows that, in many cases of service failure, failure was caused by a known mechanism which was overlooked, either by design, or elsewhere in the planning process. This paper describes one approach to designing mechanical components against failure by material deterioration, but may have application to other fields. It is based on a finding from the examination of case studies which shows that material failures follow logic structures which can be described by Boolean algebra expressions. These structures are defined as Material Failure Logic Models (MFLM’s), and can be used as a means of systematically identifying potential failure mechanisms in a complex process. The identification technique is based on the observation that MFLM’s are insensitive to the precise causes of the individual events. The paper deals primarily with problems of defining MFLM’s. Some examples of MFLM’s are given. A brief discussion is presented of a CAD system under development at the University of Illinois at Urbana-Champaign.

Failure Modes of Tapered Suction Caissons Under Vertical Pull-Out Loads

2007 ◽  
Author(s):  
Mahmood Nabipour ◽  
Mostafa Zeinoddini ◽  
Mahmood R. Abdi
Keyword(s):  
Failure Modes ◽  
Numerical Approach ◽  
Local Failure ◽  
Superior Performance ◽  
Soil Plug ◽  
Pull Out ◽  
Modes Of Failure ◽  
Numerical Studies ◽  
Second Mode ◽  
Suction Caissons

The pull-out performance of conventional upright suction caissons has been investigated by different researchers. However, no attention has been formerly paid to tapered suction caissons. Some numerical studies already conducted by the authors demonstrated that tapered caissons exhibit pull-out capacities well above than that from their corresponding upright caissons. This paper deals with different failure mechanisms of tapered suction caissons and discusses some reason for their superior performance. A numerical approach has been used and different combinations of caisson types/ soil categories have been examined. With tapered suction caissons two different modes of failure have been discerned. The first mode has been noticed to develop in weak clays and sands under drained conditions. This mode corresponds to a shear sliding failure in the soil plug along the caisson’s interior wall. Concurrently a soil wedge is formed in the soil body adjacent to the caisson. The second mode of failure has been observed in higher strength drained clays and undrained clays and sands. With this failure mode a local failure at the bottom of the soil plug has been noticed to happen. At the same time the failure is extended to the lower surfaces of a soil wedge outside of the caisson. The detached soil plug accompanies the caisson in its movement upward following the local failure.

A Numerical Study on Water Flooding in a Damaged Oil Carrier

2011 ◽  
Author(s):  
Liang-Yee Cheng ◽  
Diogo Vieira Gomes ◽  
Adriano Mitsuo Yoshino ◽  
Kazuo Nishimoto
Keyword(s):  
Numerical Study ◽  
Numerical Approach ◽  
Water Flooding ◽  
Oil Leakage ◽  
Complex Fluid ◽  
Oil Water ◽  
Moving Particle ◽  
The Stability ◽  
Fluid Solid Interaction ◽  
Interaction Problem

The objective of the present paper is to carry out numerical simulations on the coupled transient processes of oil leakage, water flooding and study of the stability in a damaged crude oil carrier. For this purpose, numerical approach based on Moving Particle Semi-Implicit (MPS) method is applied to model the complex fluid-solid interaction problem with free surface and oil-water multiphase flow. Changes on the modeling of the towing tank utilized in a previous study on oil leakage carried by the author are done to reduce the undesirable effects of the wave reflection. As a consequence, the improved results of the transient behaviors of hull motions are obtained for the cases with oil leak, as well as the final list angle and volume inside the tank in cases of water flooding. The results of the simulations show that the volume of flooded water is inversely proportional to the filling ratio. Also, the height of the opening has not significant effect on the final list and flooded volume.

scholarly journals Atmosphere loss in planet–planet collisions

2020 ◽  
Vol 496 (2) ◽  
pp. 1166-1181
Author(s):  
Thomas R Denman ◽  
Zoe M Leinhardt ◽  
Philip J Carter ◽  
Christoph Mordasini
Keyword(s):  
Specific Energy ◽  
Transition Energy ◽  
Scaling Law ◽  
The Core ◽  
Numerical Studies ◽  
Target Mass ◽  
Sufficient Energy ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Impact Energies

ABSTRACT Many of the planets discovered by the Kepler satellite are close orbiting super-Earths or mini-Neptunes. Such objects exhibit a wide spread of densities for similar masses. One possible explanation for this density spread is giant collisions stripping planets of their atmospheres. In this paper, we present the results from a series of smoothed particle hydrodynamics (sph) simulations of head-on collisions of planets with significant atmospheres and bare projectiles without atmospheres. Collisions between planets can have sufficient energy to remove substantial fractions of the mass from the target planet. We find the fraction of mass lost splits into two regimes – at low impact energies only the outer layers are ejected corresponding to atmosphere dominated loss, at higher energies material deeper in the potential is excavated resulting in significant core and mantle loss. Mass removal is less efficient in the atmosphere loss dominated regime compared to the core and mantle loss regime, due to the higher compressibility of atmosphere relative to core and mantle. We find roughly 20 per cent atmosphere remains at the transition between the two regimes. We find that the specific energy of this transition scales linearly with the ratio of projectile to target mass for all projectile-target mass ratios measured. The fraction of atmosphere lost is well approximated by a quadratic in terms of the ratio of specific energy and transition energy. We provide algorithms for the incorporation of our scaling law into future numerical studies.

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