Response of initially stressed concrete targets under high rate of loading

degradation of oil impregnated paper insulation under influence of repetitive fast high voltage impulses

در طی سالهای اخیراستفاده ازمنابع انرژی تجدید پذیر در شبکه های مدرن بنا به دلایل زیست محیطی و اقتصادی به طور گسترده استفاده شده است همچون نیروگاههای بادی و خورشیدی .ولتاژتولیدی این نیروگاهها اغلب به فرم dc می باشد وادوات الکترونیک قدرت به عنوان مبدل و پل بین شکل موج dc وac استفاده می شوند.این پروسه باعث ایجاد پالسهایی برروی شکل موج خروجی می شود که می تواند وارد تجهیزات قدرت همچون ترانسفورماتور ی...

Failure design of high-rise concrete panels under fire loading

Reinforced Concrete Wall Response under Uni- and Bi- Directional Loading

During an earthquake, structures are subjected to both horizontal and vertical shaking. Most structures are rather insensitive to variations in the vertical acceleration history and primary considerations are given to the impact of the horizontal shaking on the behavior of structures. In the laboratory, however, most component tests are carried out under uni-directional horizontal loading to si...

Effects of Loading Rate on Reinforced Concrete Beams

The effects of loading rate on the reinforced concrete beams are experimentally studied in the present paper. Firstly, the effects of strain rate on the different grades of concrete are investigated using the electro-hydraulic servo-controlled testing system at the strain rate that might be experienced during earthquakes. Based on the test results, the dynamic increasing factors (DIF) of concre...

Crack Growth and Lifetime of Concrete under Long Time Loading

Edge-notched eccentrically compressed fracture specimens made of aggregate of reduced size are loaded in standard creep test frames. Measurements of the time rate of crack mouth opening in notched concrete specimens subjected to constant load of almost one month duration are reported and analyzed. To reveal the size effect, geometrically similar specimens of four sizes in the ratio I :2:4:8 are...