Low-Velocity Perforation of Mild Steel Rectangular Plates With Projectiles Having Different Shaped Impact Faces

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Norman Jones ◽  
R. S. Birch ◽  
R. Duan
Keyword(s):  
Mild Steel ◽  
Initial Velocity ◽  
Empirical Equations ◽  
Rectangular Plates ◽  
Simple Design ◽  
Circular Plates ◽  
Low Velocity ◽  
Thick Plates ◽  
Drop Hammer ◽  
Experimental Values

This article studies the perforation of mild steel square and rectangular plates struck normally by cylindrical projectiles having blunt, hemispherical, and conical impact faces. Experimental results are obtained in a drop hammer rig for the perforation of 4mm and 8mm thick plates struck by relatively heavy projectiles weighing between 11.9kg and 200kg and traveling at an initial velocity up to about 13m∕s. The plates were struck at the center and at several positions near the fully clamped supports. The effect of the aspect ratio on the perforation energies of rectangular plates is examined, and comparisons are made with the perforation behavior of fully clamped circular plates. The predictions of several empirical equations are compared with the corresponding experimental values of the perforation energies. Simple design equations are also presented for predicting the maximum permanent transverse displacements of square plates prior to any cracking or perforation.

Response of Mild Steel Pipes Under High Mass Low Velocity Impacts

2014 ◽  
Author(s):  
Shamsoon Fareed ◽  
Ian May
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Impact Energy ◽  
High Mass ◽  
Low Velocity ◽  
Element Analysis ◽  
Steel Pipes ◽  
Impact Tests ◽  
The Finite Element Analysis ◽  
The Impact

Accidental loads, for example, due to heavy dropped objects, impact from the trawl gear and anchors of fishing vessels can cause damage to pipelines on the sea bed. The amount of damage will depend on the impact energy. The indentation will be localized at the contact area of the pipe and the impacting object, however, an understanding of the extent of the damage due to an impact is required so that if one should occur in practice an assessment can be made to determine if remedial action needs to be taken to ensure that the pipeline is still serviceable. There are a number of parameters, including the pipe cross section and impact energy, which influence the impact behaviour of a pipe. This paper describes the response, and assesses the damage, of mild steel pipes under high mass low velocity impacts. For this purpose full scale impacts tests were carried out on mild steel pipe having diameter of 457 mm, thickness of 25.4 mm and length of 2000 mm. The pipe was restrained along the base and a 2 tonnes mass with sharp impactor having a vertical downward velocity of 3870 mm/sec was used to impact the pipe transversely with an impact energy of 16 kJ. It was found from the impact tests that a smooth indentation was produced in the pipe. The impact tests were then used for validation of the non-linear dynamic implicit analyses using the finite element analysis software ABAQUS. Deformations at the impact zone, the rebound velocity, etc, recorded in the tests and the results of the finite element analysis were found to be in good agreement. The impact tests and finite element analyses described in this paper will help to improve the understanding of the response of steel pipes under impact loading and can be used as a benchmark for further finite element modelling of impacts on pipes.

An Experimental Study on the Lateral Impact of Fully Clamped Mild Steel Pipes

1992 ◽  
Vol 206 (2) ◽  
pp. 111-127 ◽  
Author(s):  
N Jones ◽  
S E Birch ◽  
R S Birch ◽  
L Zhu ◽  
M Brown
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Mild Steel ◽  
Failure Modes ◽  
Experimental Results ◽  
Lateral Impact ◽  
Drop Hammer ◽  
Steel Pipes ◽  
Scale Range ◽  
The Impact

This report presents some experimental data that were recorded from 130 impact tests on mild steel pipes in two drop hammer rigs. The pipes were fully clamped across a span which was ten times the corresponding outside pipe diameters which lie between 22 and 324 mm. All of the pipes except five had wall thicknesses of 2 mm approximately and were impacted laterally by a rigid wedge indenter at the mid span, one-quarter span or near to a support. The impact velocities ranged up to 14 m/s and caused various failure modes. Some comparisons between two sets of experimental results indicate that the laws of geometrically similar scaling are almost satisfied over a scale range of approximately five.

Creep Prediction Model for Concrete Made of Crushed Clay Bricks as Coarse Aggregate

2012 ◽  
Vol 166-169 ◽  
pp. 994-997 ◽  
Author(s):  
Syed Ishtiaq Ahmad ◽  
Sushanta Roy
Keyword(s):  
Coarse Aggregate ◽  
Generalized Equation ◽  
Time Behavior ◽  
Simple Design ◽  
Clay Bricks ◽  
Design Office ◽  
Proposed Model ◽  
Creep Time ◽  
Experimental Values ◽  
Two Parameters

A simple design office oriented empirical model containing only two parameters has been developed to predict creep behavior of concrete made of crushed clay bricks as coarse aggregate. For this, concrete samples having three different normal compressive strengths in the range of 18.9 up to 24.0 N/mm2 are first prepared and then tested for their creep deformation. For each of the samples, a hyperbolic equation is developed from their creep-time behavior. These equations are then combined and modified according to statistical norms to finally obtain a generalized equation. Comparison of creep strain obtained from this equation with that of experimental values show that the proposed model can closely predict creep in brick aggregate made concrete.

The Calibration of Thermocouples by Freezing-Point Baths and Empirical Equations

1959 ◽  
Vol 81 (2) ◽  
pp. 177-188 ◽  
Author(s):  
R. P. Benedict
Keyword(s):  
Digital Computer ◽  
High Speed ◽  
Freezing Point ◽  
Individual Characteristics ◽  
Empirical Equations ◽  
Test Results ◽  
Calibration System ◽  
Temperature Range ◽  
Experimental Values ◽  
The Individual

A calibration system is described which is based on the use of a few precisely determined experimental values obtained from freezing-point baths. Characteristics of the individual thermocouples at intermediate points are obtained by passing empirical equations of prescribed form through the test values. A program is reviewed, by which a high-speed digital computer accomplishes the necessary conversions, curve fittings, comparisons of individual characteristics with arbitrary reference tables, and the printing out of a table of differences. Test results for a series of iron-constantan thermocouples, over the temperature range 32–1225 F, are presented to illustrate the use of the system and the uncertainties involved. Comparisons are drawn between these results and those obtained by other methods.

Analytical analysis of jute–epoxy beams subjected to low-velocity impact loading

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Manar Hamid Jasim ◽  
Ali Mohammad Ali Al-Araji ◽  
Bashar Dheyaa Hussein Al-Kasob ◽  
Mehdi Ranjbar
Keyword(s):  
Contact Force ◽  
Initial Velocity ◽  
Ritz Method ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Content Type ◽  
Velocity Impact ◽  
Simply Supported ◽  
Force Impact ◽  
Fourth Order Method

PurposeIn the article, analytical model of first-order shear deformation (FSDT) beams made of jute–epoxy is presented to study the low-velocity impact response.Design/methodology/approachThe nonlinear Hertz contact law is applied to identify the contact between projectile and beam. The energy method, Lagrange's equations and Ritz method are applied to derive the nonlinear governing equation of the beam and impactor-associated boundary condition. The motion equations are then solved simultaneously by the Runge–Kutta fourth-order method.FindingsAlso, a comparison is performed to validate the model predictions. The contact force and beam indentation histories of the jute–epoxy simply supported beam under spherical impactor with different radius and initial velocity are investigated in detail. It is found that in response to impactor radius increase, the utilization of the contact force law has resulted in a same increasing trend of peak contact force, impact duration and beam indentation, while in response to impactor initial velocity increase, the maximum contact force and beam indentation increase while impact time has vice versa trend.Originality/valueThis paper fulfills an identified need to study how jute–epoxy beam behavior with simply supported boundary conditions under low-velocity impact can be enabled.

The Plastic Bending of Heavily Curved Beams

1957 ◽  
Vol 61 (564) ◽  
pp. 824-830
Author(s):  
W. Johnson ◽  
B. W. Senior
Keyword(s):  
Mild Steel ◽  
Yield Stress ◽  
Cross Section ◽  
Compressive Load ◽  
Constant Cross Section ◽  
Curved Beams ◽  
Plastic Bending ◽  
Experimental Values ◽  
Plastic Stress

It is shown that when heavily curved circular beams of constant cross section are subjected to a compressive load along the “open” diameter, the load for the start of significant deformation as indicated by the reduction in diameter along the line of action of the load, may be estimated by the use of rectangular plastic stress blocks based on the yield stress of the material. Comparison of the experimental values obtained on specimens of duralumin and mild steel with those predicted theoretically are, on the whole, only slightly underestimated.

Impulsive Loading of a Simply Supported Circular Rigid Plastic Plate

1968 ◽  
Vol 35 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Norman Jones
Keyword(s):  
Yield Condition ◽  
Impulsive Loading ◽  
Bending Moments ◽  
Circular Plates ◽  
Governing Equations ◽  
Rigid Plastic ◽  
Static Loads ◽  
Simply Supported ◽  
Experimental Values ◽  
Theoretical Procedure

It is clear from a survey of literature on the dynamic deformation of rigid-plastic plates that most work has been focused on plates in which either membrane forces or bending moments alone are considered important, while the combined effect of membrane forces and bending moments on the behavior of plates under static loads and beams under dynamic loads is fairly well established. This paper, therefore, is concerned with the behavior of circular plates loaded dynamically and with deflections in the range where both bending moments and membrane forces are important. A general theoretical procedure is developed from the equations for large deflections of plates and a simplified yield condition due to Hodge. The results obtained when solving the governing equations for the particular case of a simply supported circular plate loaded with a uniform impulsive velocity are found to compare favorably with the corresponding experimental values recorded by Florence.

Finite Element Simulation and Experimental Studies on Projectile Perforation of Circular and Rectangular Plates

2016 ◽  
Vol 715 ◽  
pp. 68-73
Author(s):  
Koki Yamada ◽  
Tomoki Moroe ◽  
Masahiro Nishida ◽  
Koji Mizutani ◽  
Shingo Enomoto ◽  
...  
Keyword(s):  
Fracture Strain ◽  
Experimental Studies ◽  
Mesh Size ◽  
Impact Point ◽  
Rectangular Plates ◽  
Circular Plates ◽  
Materials Properties ◽  
Limit Velocity ◽  
Element Simulation ◽  
Aluminum Alloy 2024

Experiments and simulations on projectile impact to circular and rectangular plates made of aluminum alloy 2024-T3 were carried out. Ballistic limit and deformation of circular plates and rectangular plates at impact point were examined. The experimental results were compared with the simulation ones which calculated using the materials properties experimentally obtained. The effects of mesh size and fracture strain on both the crack limit velocity and the perforate limit velocity were discussed.

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