Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Engineering Transactions

2 2011

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Strain rate behaviour of three rocks in tension

Cadoni E., Antonietti S., Dotta M., Forni D.

Engineering Transactions

2011

Vol. 59, iss. 3

197-210

The paper presents the dynamic characterization in tension of three rocks under medium and high strain-rates. The tests have been carried out by means of the JRC-Split Hopkinson Tension Bar and an Hydro-Pneumatic Machine, installed in the DynaMat Laboratory of the University of Applied Sciences of Southern Switzerland. The dynamic direct tension tests have been performed at 3 different strain rates (0.1, 10, 100 strain/second) on an orthogneiss, for loading directions 0, 45and 90 respect to the schistosity, and two different types of marble. Results of the tests show a significantly strain-rate sensitive behaviour, exhibiting dynamic tensile strength increasing with strain-rate. In order to describe the strain rate behaviour of these rocks, the dynamic increase factors in function of the strain rates for tensile strength have been used.

Mechanical characterization of steel for fastening in a wide range of strain rate

Cadoni E., Bragov A. M., Dotta M., Forni D., Konstantinov A., Lomunov A., Ripamonti A.

Engineering Transactions

2011

Vol. 59, iss. 2

101-117

In this paper, the preliminary results of the mechanical characterization in a wide range of strain rate of the 30MnB4 steel, usually adopted for fasteners, are described. In this study the di?erent issues required to implement the dynamic test results in numerical code have been analyzed. Different experimental techniques have been used for di?erent strain rates: univer- sal machine, Hydro-Pneumatic Machine, JRC-Modi?ed Hopkinson Bar and Split Hopkinson Pressure Bar. The failure at high strain rate has been examined by means of fast digital image recording systems. The material shows enhanced mechanical properties increasing the strain rate: this fact can be taken into consideration to improve the product design and the manu- facturing process. The experimental research has been developed in the DynaMat laboratory of the University of Applied Sciences of Southern Switzerland and in the Laboratory of Dy- namic Investigation of Materials in Nizhny Novgorod, in the frame of the Swiss – Russian Joint Research Program.