Experimental investigation of blast loading on an airfoil in mach 0.7 airflow with initial angle-of-attack change of 28 deg

Blast loading on airfoil in Mach 0.7 airflow with initial angle of attack change of 28 deg - model experiment

Experimental and Numerical Investigations of Pressure Field of Curved Shell Structure Subjected to Interior Blast

© 2019 Jialu Ma et al. A terrorist attack on a long-span spatial structure would cause horrible results. Therefore, it is important to determine the characteristics of blast pressure fields to protect such structures. In this study, fully confined blast loading tests were conducted using a rigid curved shell model, which had an inner space similar to that of a reticulated dome. Four different scenarios were carried out to record the blast loading on five typical positions. The blast pressure-time data were compared and analyzed. In addition, a suitable numerical simulation method was proposed for the issues involved in interior blast loading. This numerical model was verified by comparing with the test data. A parametrical analysis of the interior blast simulations was conducted based on this numerical method. The blast loading values at specific positions were obtained with the key parameters varied within a reasonable scope. The blast loading from blast tests and simulations were presented. On this basis, the interior blast loading could conveniently be predicted by using the method and data in this paper, which could be used in the protective design of other reticulated domes

Experimental and numerical study on axial impact loading of pultruded composite tubes

The application of fibre reinforced composites has been increasing in the area of impact and blast loading of structures. The major advantages of these materials over metals are higher specific energy absorption, more economical, low weight and less maintenance. In this work, an attempt is made to study the energy absorption characteristics of unidirectional pultruded composite tubes. Two different cross sections (circular and square) were used for the study. To absorb more energy during the impact or blast loading the composite tubes have to deform progressively. To induce the progressive deformation of composite tubes two different types of triggering mechanisms were used. The energy absorption of each tube was studied experimentally. A new approach was adopted using cohesive elements for the numerical assessment of the energy absorbing capability of composite tubes. Finally the experimental and numerical results were compared

Modelling and simulation of the effect of blast loading on structures using an adaptive blending of discrete and finite element methods

We present a new computational model for predicting the effect of blast loading on structures. The model is based in the adaptive coupling of the finite element method (FEM) and the discrete element method (DEM) for the accurate reproduction of multifracturing and failure of structures under blast loading. In the paper we briefly describe the basis of the coupled DEM/FEM technology and demonstrate its efficiency in its application to the study of the effect of blast loading on a masonry wall, a masonry tunnel and a double curvature dam.Postprint (published version

Modelling and simulation of the effect loading on structures using and adaptive blending of discrete and finite element methods

We present a new computational model for predicting the effect of blast loading on structures. The model is based in the adaptive coupling of the finite element method (FEM) and the discrete element method (DEM) for the accurate reproduction of multifracturing and failure of structures under blast loading. In the paper we briefly describe the basis of the coupled DEM/FEM technology and demonstrate its efficiency in its application to the study of the effect of blast loading on a masonry wall, a masonry tunnel and a double curvature dam

Low-impulse blast behaviour of fibre-metal laminates

This paper presents three dimensional (3D) finite element (FE) models of the low-impulse localised blast loading response of fibre-metal laminates (FMLs) based on an 2024-O aluminium alloy and a woven glass-fibre/polypropylene composite (GFPP). A vectorized user material subroutine (VUMAT) is developed to define the mechanical constitutive behaviour and Hashin’s 3D failure criteria incorporating strain-rate effects in the GFPP. In order to apply localised blast loading, a user subroutine VDLOAD is used to model the pressure distribution over the exposed area of the plate. These subroutines are implemented into the commercial finite element code ABAQUS/Explicit to model the deformation and failure mechanisms in FMLs. The FE models consider FMLs based on various stacking configurations. Both the transient and permanent displacements of the laminates are investigated. Good correlation is obtained between the measured experimental and numerical displacements, the panel deformations and failure modes. By using the validated models, parametric studies can be carried out to optimise the blast resistance of FMLs based on a range of stacking sequences and layer thicknesses

Dynamic Deformation of Clamped Circular Plates Subjected to Confined Blast Loading

In this paper, the dynamic deformation of thin metal circular plates subjected to confined blast loading was studied using high-speed three-dimensional Digital Image Correlation (3D DIC). A small-scale confined cylinder vessel was designed for applying blast loading, in which an explosive charge was ignited to generate blast loading acting on a thin metal circular plate clamped on the end of the vessel by a cover flange. The images of the metal plates during the dynamic response were recorded by two high-speed cameras. The 3D transient displacement fields, velocity fields, strain fields and residual deformation profiles were calculated by using 3D DIC. Some feature deformation parameters including maximum out-of-plane displacement, final deflection, maximum principal strain and residual principal strain were extracted, and the result was in good agreement with that simulated by AUTODYN. A dimensionless displacement was introduced to analyse the effects of plate thickness, material types and charge mass on the deflection of metal plates. DIC is also proven to be a powerful technique to measure dynamic deformation under blast loading

Numerical simulation of ultra high performance fibre reinforced concrete panels subjected to blast loading

AbstractIn the last few decades, several full-scale blast tests have been performed to study the behaviour of ultra high performance fibre reinforced concrete (UHPFRC). However, only limited research has been devoted to simulate performance of UHPFRC subjected to blast loading. This paper presents a numerical investigation on the performance of UHPFRC under blast loading with a concrete material model which takes into account the strain rate effect. Furthermore, the model is modified to better express the strain softening of UHPFRC material. The performance of the numerical models is verified by comparing modelling results to the data from corresponding full scale blast tests. With the verified models, parametric studies are also carried out to investigate the effect of steel reinforcement and steel fibre in increasing UHPFRC resistance to blast loading

The Influence of the Stiffened Plate Distance to the Ultimate Strength under Blast Loading Condition

The ultimate strength is one of the most important aspect in all design criteria. Blast or explosion may takes place on the offshore structure and it is a catastrophic failure with small probability and cannot be predicted. The stiffened plate distance has significant influence to the ultimate strength under blast loading condition. In order to know the influence, the analysis must be conducted. In the present study, the analysis of the influence of the stiffened plate distance is performed using The Non-Linear Finite Element Method (FEM) code ANSYS. The investigation of the stiffened plate is located at the deck part of the structure. The stiffened plate distance is varied to know the influence due to blast loading. The blast loading is assumed to be applied in vertical direction combined with the uniaxial thrust. The fixed supported of boundary condition is applied along the side of the stiffened plate. The result obtained by the FE analysis for the influence of the stiffened plate to the ultimate strength under blast loading is compared for any stiffened plate distance and the behavior of the ultimate strength including post ultimate strength is also presented in this paper

EXPERIMENTAL STUDY OF BLAST RESISTANT GLAZING SYSTEM RESPONSE TO EXPLOSIVE LOADING

This thesis recounts the experimental study of the dynamic response of a blast resistant glazing system to explosive loading. A combination of triaxial force sensors, pressure gauges, and laser displacement gauges capture the response in detail over a wide range of scenarios. The scenarios include low level blast loading to characterize the reaction at points around the perimeter of the window, moderate level blast loading to examine the repeatability of the blast scenario, and high level blast loading to capture the response during failure as the tensile membrane forms. The scenarios are modeled via an analytical Single-Degree-of-Freedom model as well as finite element modeling in ANSYS Explicit Dynamics. In addition, this study investigates some of the differences between experimental data and the predictions made by modeling