A Study on the Large Ductile Deformations and Perforation of Mild Steel Plates Struck by a Mass—Part I: Experimental Results

1997 ◽  
Vol 119 (2) ◽  
pp. 178-184 ◽  
Author(s):  
N. Jones ◽  
S.-B. Kim

An experimental study is reported on the ductile deformation and perforation of plates struck at the center by solid cylindrical projectiles having the longitudinal axis normal to the plate surface. The plates, which are made from 4 to 8-mm-thick mild steel sheet, are fully clamped around a circular boundary and are struck by projectiles having blunt ends and traveling with impact velocities within the range 7.7–118.9 m/s. Comparisons are made in Part II with the static perforation behavior and with previously published experimental results and several empirical equations for the impact case. A new empirical equation, which retains the influence of the impact velocity on the perforation energy, is also proposed in Part II.

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Norman Jones ◽  
R. S. Birch

Experimental results are reported for the perforation of geometrically similar fully clamped circular and square mild steel plates struck transversely by cylindrical projectiles having blunt, conical, and hemispherical noses. The striking masses are much heavier than the corresponding plate mass and travel with initial impact velocities up to about 12m∕s. The blunt projectiles perforate the plating easiest, while the hemispherical-nosed ones require the greatest energy. The perforation energy of a conical-nosed projectile is somewhat less than that for a hemispherical-nosed one. The data are used to explore the validity of the geometrically similar scaling laws over a geometric scale range of 4. The experimental results are compared to the empirical equations for the impact perforation of plates and with theoretical rigid-plastic predictions for the large ductile deformation behavior of those test specimens, which did not suffer cracking or perforation. The experimental results satisfy the requirements of geometrically similar scaling and some simple equations are presented, which are useful for design purposes.


1997 ◽  
Vol 119 (2) ◽  
pp. 185-191 ◽  
Author(s):  
N. Jones ◽  
S.-B. Kim

An experimental study into the ductile deformations and static and impact perforation of mild steel plates is reported in Part I. These results are discussed in this article and compared with other experimental data reported in the literature. The accuracy of various empirical formulas for the impact perforation of plates is also examined.


Author(s):  
N Jones ◽  
S E Birch ◽  
R S Birch ◽  
L Zhu ◽  
M Brown

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.


2021 ◽  
Vol 42 (2) ◽  
Author(s):  
Mariusz Kormanek ◽  
Jiří Dvořák

Ground contact pressures exerted by elements of the machine chassis on the ground in the forest are associated with the machine impact on the soil during its operation. In the case of a crawler system, determining the ground contact pressure appears simple, which is not entirely true. The aim of the study was to analyze the loads on the ground (forest soil) exerted by the MHT 8002HV crawler harvester chassis. The measurements were made in Forest School Enterprise in Kostelec nad Černými Lesy, Central Bohemia Region in the Czech Republic, on brown soil made of clay on stony formations, fresh mixed mountain forest (FMMF), with the use of a hydraulic scale when extending the harvester crane forward along and perpendicular to the longitudinal axis of the machine. The calculations were carried out with a simulated load of the crane on the tree in question, assuming that the impact on the ground of the crawler system is heterogeneous and that the point impact comes from the crawler support wheels. As it was shown, the average ground contact pressures under the crawler track of the analyzed harvester generally do not exceed 70 kPa. The crane extension with a simulated load, which would have caused the crawler track to act on the ground with an average pressure exceeding 70 kPa, was limited by machine stability. On the other hand, high ground contact pressures may occur under a more loaded section of the crawler track if the active length of the crawler track is shortened. As it was shown in the case of a weak track tension, the course of ground contact pressures exerted on the soil deviates from the assumed usually homogeneous impact over the entire length of the crawler.


1997 ◽  
Vol 119 (3) ◽  
pp. 332-342 ◽  
Author(s):  
N. Jones ◽  
S.-B. Kim ◽  
Q. M. Li

A theoretical analysis is presented in this paper to predict the dynamic plastic response of aluminium alloy and mild steel circular plates when struck normally by blunt solid cylindrical masses at the center. Reasonable agreement is obtained with experimental results for the permanent transverse displacements. Different failure mechanisms, which have been found in previous experimental studies on aluminium alloy and mild steel plates, are also illustrated by the proposed theory.


2018 ◽  
Vol 10 (2) ◽  
pp. 174-197 ◽  
Author(s):  
Senthil Kasilingam ◽  
Mohd Ashraf Iqbal ◽  
Rupali Senthil

This study is based on the finite element investigation of the response of mild steel and Armox 500 T steel targets subjected to macro- and micro-size impactor. The simulations were carried out on target against penetrator with varying masses, sizes, shapes and different nature (rigid and deformable projectiles) using ABAQUS/Explicit. The material parameters of Johnson–Cook elasto-viscoplastic model were employed for predicting the behaviour of the target. The impact resistance of mild steel and Armox 500 T steel plates has been studied against flat nose having masses of 4, 8, 13.5, 27, 32 and 64 kg. The influence of temperature has also been studied numerically for particular penetrator. To study the influence of nature of projectile, the simulations were performed on mild steel and Armox 500 T steel targets against deformable 2024 aluminium flat, hardened steel flat and hardened steel conical impactors at 950 and 150 m/s incidence velocities. Also, the simulations were carried out on given target against 7.62 and 12.7 mm armour piercing incendiary ogival nose projectiles. The performance of (4.7 + 4.7 mm) 9.4-mm-thick equivalent mild steel and Armox 500 T steel plate in combination has also been studied against 7.62 armour piercing incendiary ogival nose projectiles at 950 and 150 m/s incidence velocities. The study thus presents a detailed investigation in terms of penetration, perforation and failure mechanism of mild steel and Armox 500 T steel target and leads to some important conclusions pertaining to the force and resistance offered by the target.


2016 ◽  
Author(s):  
Leonardo Becchetti ◽  
Maurizio Fiaschetti ◽  
Francesco Salustri

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