Computational Techniques for Structural Damage and Failure

2009 ◽  
Author(s):  
W.B. Krätzig ◽  
Y. Petryna ◽  
F. Chen
Keyword(s):  
Structural Damage ◽  
Computational Techniques ◽  
Damage And Failure

scholarly journals Acoustic emission description from a damage and failure scenario of rotomoulded polyolefin sandwich structure subjected to internal pressure for storage applications

2020 ◽  
Vol 21 (1) ◽  
pp. 105 ◽  
Author(s):  
Eric Lainé ◽  
Jean-Claude Grandidier ◽  
Maxime Cruz ◽  
Anne-Laure Gorge ◽  
Claire Bouvy ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Structural Damage ◽  
Sandwich Structure ◽  
Water Pressure ◽  
Average Frequency ◽  
Polymer Structure ◽  
Foam Core ◽  
Damage And Failure ◽  
Failure Scenario ◽  
Polyethylene Sample

The aim of this paper is to study the damage mechanisms in a sandwich polymer structure that contains three layers: two polyolefin skins and the foam core (skin–foam–skin). Specific tests on structure associated with the acoustic emission (AE) technique and tomographic observations (RX) are used to identify the damage. Initially, a conventional tensile test was performed to correlate the acoustic emission with the initiation of plasticity and damage to a polyethylene sample. The results obtained are close to those observed in other studies and it is possible to separate the signal from cavitation and propagation of necking. The technique is then employed to capture the rupture of a polymer skin on a multilayer rotomoulded structure (bottle). Tests were carried out on this bottle under internal water pressure. Three tests are performed with more or less early interruptions in order to identify the first damage and understand their evolution. Different quantities (average frequency, RA value, etc.) are observed in order to quantify and understand the perceived damage. With the AE/RX correlation and mechanical behaviour, a scenario of structural damage is proposed.

Numerical Simulation on Damage and Failure of Recycled Aggregate Concrete with a Lattice Model

2009 ◽  
Vol 417-418 ◽  
pp. 689-692 ◽  
Author(s):  
Jian Zhuang Xiao ◽  
Qiong Liu ◽  
Vivian W.Y. Tam
Keyword(s):  
Lattice Model ◽  
Structural Damage ◽  
Fortran Program ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Model ◽  
Mixture Ratio ◽  
Aggregate Concrete ◽  
Damage And Failure ◽  
Random Aggregate

A random aggregate model of recycled aggregate concrete is developed in this paper on the base of a mixture ratio. Combining a lattice model with random aggregate of recycled aggregate concrete, lattice elements in the lattice model of recycled aggregate concrete can be classified into five types: (1) nature aggregate, (2) old hardened mortar, (3) new hardened mortar, (4) old interface transition zone (ITZ), and (5) new ITZ. The fundamental mechanical parameters of the lattice elements are chosen from the authors’ test as well as other references. A FORTRAN program of the lattice model is then written with basic theories of finite element method (FEM) for simulating the meso-structural damage of recycled aggregate concrete under uniaxial compression.

Nonlinear Dynamic Finite Analysis of BFRP-Strengthened Masonry Structure Based on ABAQUS

2014 ◽  
Vol 936 ◽  
pp. 1331-1335
Author(s):  
Zhen Lei ◽  
Yong Wang ◽  
Jun Tong Qu
Keyword(s):  
Nonlinear Dynamic ◽  
Structural Damage ◽  
Failure Process ◽  
Dynamical Analysis ◽  
Base Shear ◽  
Confined Masonry ◽  
Damage And Failure ◽  
Before And After ◽  
Concrete Damage ◽  
Strengthening Technique

The externally bonded FRP is an effective strengthening technique, which is mainly verified through laboratory tests. In this paper, numerical analysis models were established in ABAQUS respectively based on an experimental scaled three-story confined masonry structures before and after strengthened with BFRP. Then dynamical analysis considering material nonlinearity, geometric nonlinearity and contact nonlinearity was carried out on these two models. Here, representative volume element method was used to simplify the simulation of masonry. Besides, concrete damage plasticity model was adopted to simulate the structural damage and failure process. The reliability and accuracy of nonlinear dynamic finite analysis were validated by comparing the numerical simulation results and experimental results in terms of dynamic property, displacement and acceleration response and the maximum base shear.

Using Explicit Finite Element Analysis to Simulate the Structural Damage Associated With an Internal Detonation in a Heat Exchanger

2014 ◽  
Author(s):  
Phillip E. Prueter
Keyword(s):  
Finite Element ◽  
Heat Exchanger ◽  
Structural Damage ◽  
Real Life ◽  
Blast Loading ◽  
Process Equipment ◽  
Computational Techniques ◽  
Explicit Finite Element ◽  
Blast Analysis ◽  
External Blast Loading

Developing the realistic blast loading associated with an internal detonation occurring within a pressure vessel or heat exchanger is challenging. Unlike evaluation of external blast loading on structures due to far-field explosions, where typical overpressure-time histories can be reasonably defined based on empirical data, investigating confined detonations presents additional complications. The subsequent impulsive peak reflected overpressure from confined detonations acting on a structure can be extremely high due to the close proximity of the blast source to the vessel wall or pressure boundary. This establishes the possibility of significant structural damage for process equipment subjected to an internal detonation, even for relatively modest amounts of concentrated explosive products. This paper discusses the underlying theory of blast analysis and examines the practical application of non-linear, finite element based, explicit computational techniques for simulating the load acting on a structure due to internal and external blasts. The investigation of a recent, real-life industry failure of a heat exchanger due to a suspected internal detonation is discussed. Explicit, three-dimensional blast analysis is performed on the heat exchanger in question, and an internal detonation is simulated to reasonably replicate the considerable damage actually observed in the field. This analysis permits the determination of an approximate amount of concentrated product that caused the accidental explosion; that is, the plausible equivalent amount of explosives is back-calculated based on the predicted damage to the finite element model of the equipment in question. Computational iterations of varying charge amounts are performed and the predicted amount of permanent damage is documented so sensitivity to the hypothesized charge amount can be quantified. Furthermore, explicit blast analysis of nearby equipment is performed. In this investigation, computational results for both the heat exchanger (subjected to internal blast loading) and surrounding equipment (subjected to external blast loading) are in good agreement with the measured plastic deformations and failure modes that were actually observed in the field. Commentary on the likely detonation event that caused the significant damage observed is provided. Additionally, an advanced finite element failure criterion that is driven by plastic yielding is employed where portions of the computational model are removed from the simulation once a user-defined strain threshold is reached. This approach facilitates simulation of the gross heat exchanger pressure boundary failure actually observed in this case. The explicit finite element based analyses discussed in this study reasonably predict the structural response and damage characteristics corresponding to a recent, real-life industry failure.

scholarly journals Experimental Study on the Damage and Deterioration Behaviour of Deep Soft Rock under Water-Rock Interaction

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zenghui Zhao ◽  
Hao Liu ◽  
Xianzhou Lyu ◽  
Lei Wang ◽  
Zhongxi Tian ◽  
...  
Keyword(s):  
Water Content ◽  
Structural Damage ◽  
Soft Rock ◽  
Rock Interaction ◽  
Damage And Failure ◽  
Saturated Water ◽  
Diffusion Migration ◽  
Exchange Adsorption ◽  
Water Saturated ◽  
Water Contents

The ageing disintegration, the damage, and failure mechanism of water-saturated soft rock are of significance to hazard prevention for deep mining. In this paper, indoor experiments, including disintegration behaviour tests in water, uniaxial compression failure tests of rock samples with different water contents, and variations in the microstructure of mudstone under saturated water contents, were conducted. The investigation results show that the saturated water content of mudstone is 16.96% and that the rock mass bursts completely after being immersed in water for 72 h. With increasing water content, the uniaxial strength and elastic modulus at the prepeak stage present significant attenuation. However, Poisson’s ratio varies little, which indicates that the swelling of cemented mudstone is not obvious when meeting water. In addition, the failure pattern of mudstone changes from overall splitting failure to block fragmentation failure. Due to ion-exchange adsorption and the wedging action of water molecules, the edge of contact between particles changes from staggered to smooth, which leads to the expansion of pores, the loosening of mudstone structures, and a decrease in mechanical strength. Therefore, the diffusion, migration, and particle expansion of illite and other clay minerals in mudstone are the main factors leading to the structural damage and strength reduction of weakly cemented rock under water-rock interactions.

HIGH FIDELITY BUILDING BLOCK AND VALIDATION PROTOCOLS FOR NEXTGEN COMPOSITE METHODS

2021 ◽  
Author(s):  
JOSEPH D. SCHAEFERBRIAN ◽  
P. JUSTUSSON ◽  
BRIAN P. JUSTUSSON
Keyword(s):  
Building Block ◽  
Material Behavior ◽  
Image Correlation ◽  
Computational Techniques ◽  
High Fidelity ◽  
Micro Computed Tomography ◽  
Material Models ◽  
Damage And Failure ◽  
Composite Methods ◽  
Modeling Strategy

The High Fidelity Building Block and Validation Protocols for NextGen Composite Methods Program (N00014-21-C-1008) seeks to provide industry with the critical experimental data and supporting guidelines by which to evaluate, validate, and demonstrate the predictive capabilities of advanced computational analysis tools. Following from the successful development of a coupon level database (N00014-14-C-0128), the HiFi NextGen program focuses on the subelement and element levels of the design-test-certification building block wherein the greatest expense for design substantiation is incurred. Additionally, data is developed to provide improved understanding of fundamental material behavior for composite material models. Advanced inspection techniques such as digital image correlation and in-situ micro computed tomography are used to capture damage onset, damage propagation, and ultimate failure within representative composite structure test specimens. Where applicable, the test program includes relevant environmental conditions. Validation guidelines focus on the use of emerging progressive damage and failure analysis (PDFA) computational techniques and address modeling considerations such as length scale, material models, numeric implementation, mesh objectivity, modeling strategy, and computational scalability. All test articles are fabricated from IM7/5320-1 tape and fabric as well as FM309-1 structural adhesive to maintain a high degree of relevancy for future aircraft needs.

scholarly journals Numerical simulation of the dynamic response in pulse-loaded fibre–metal-laminated plates

2016 ◽  
Vol 7 (4) ◽  
pp. 469-494 ◽  
Author(s):  
Ebuka Nwankwo ◽  
Arash Soleiman Fallah ◽  
Mojtaba Moatamedi ◽  
Luke A Louca
Keyword(s):  
Dynamic Response ◽  
Structural Damage ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Laminated Plates ◽  
Damage Initiation ◽  
Structural Support ◽  
Damage And Failure ◽  
Composite Glass ◽  
Fibre Metal

This article presents a three-dimensional constitutive model to replicate the dynamic response of blast-loaded fibre–metal laminates made of 2024-0 aluminium alloy and woven composite (glass fibre–reinforced polypropylene). Simulation of the dynamic response is challenging when extreme localised loads are of concern and requires reliable material constitutive models as well as accurate modelling techniques. It is well known that back layers in a fibre–metal laminate provide structural support for front layers; thus, proper modelling of constituent failure and degradation is essential to understanding structural damage and failure. The improved developed model to analyse damage initiation, progression and failure of the composite is implemented in finite element code ABAQUS, and a good correlation is observed with experimental results for displacements of the back and front faces as presented by other researchers. The model was also able to predict accurately the tearing impulses. Finally, the concepts of the ‘efficiency of the charge’ and ‘effectiveness of the target’ are proposed in the context of localised blast loading on a structure. Dimensionless parameters are introduced to quantify these parameters.

Assessment of structural damage and failure

2001 ◽  
Vol 71 (1) ◽  
pp. 1-15 ◽  
Author(s):  
W. B. Krätzig ◽  
Y. S. Petryna
Keyword(s):  
Structural Damage ◽  
Damage And Failure

Effect of particle mass concentration on erosion characteristics of self-priming pump

2021 ◽  
pp. 095440622110007
Author(s):  
Wenqi Zhang ◽  
Shuai Yang ◽  
Dazhuan Wu ◽  
Jiegang Mou
Keyword(s):  
Structural Damage ◽  
Leading Edge ◽  
Discrete Phase Model ◽  
Suction Surface ◽  
Two Phase ◽  
Lower Velocity ◽  
Damage And Failure ◽  
Discrete Phase ◽  
Flow Medium ◽  
Solid Liquid

The self-priming pump is widely used in conveying the solid-liquid two-phase flow medium. The particles in the medium erode the components, leading to structural damage and failure. The computational fluid dynamics (CFD) model of the 65ZW30-20 self-priming pump is built to study erosion characteristics and mechanisms. FLUENT, along with the Discrete Phase Model and Oka erosion model, is applied for the numerical simulation. The particle distribution, impact times and velocity, and trajectories are taken into consideration to investigate the erosion characteristics in each component. The results show that with the increase of the particle concentration, the head and efficiency decreases gradually. The volute wall and blade leading edge are the most vulnerable regions to erosion, because of a large number of impact times and high impact velocity. Also, the particles impact the front gap wall for fewer times and the hub with lower velocity, which leads to a slighter erosion. Besides, the particle trajectories indicate that some particles impact the blade suction surface and the paraxial area of the shroud, rendering considerable erosion.

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