Numerical analyses of long carbon fiber reinforced concrete panels exposed to dynamic loading.

摘要

The purpose of this research was to evaluate impact and blast performance of long carbon fiber reinforced concrete experimentally and numerically. Experimental tests were conducted on plain concrete (PC), reinforced concrete, and four different types of long carbon fiber reinforced concrete (LCFRC). The results from each test were then compared to one another. This comparison indicates that adding long carbon fibers to concrete both increases the post-cracking behavior of concrete and decreases the spalls in either an impact or blast test. Among all of the fibers tested, Fiber Type B3 outperformed the other fibers, absorbing more energy during impact. Numerical simulation of a drop weight impact test was then performed on both welded wire reinforced concrete and long carbon fiber reinforced concrete panels. The three-dimensional finite element code LS-DYNA was used for the numerical analyses. Three different, simple input models were used to simulate concrete behavior under impact. As a consequence, both the force time history and deflection time history at failure were obtained for each case. These results were compared together. Then, a series of tests were conducted to compare the blast resistance of panels constructed with either conventional reinforced concrete (RC) or long carbon fiber-reinforced concrete (LCFRC). A finite element model was created in LS-DYNA to replicate both a control panel and an LCFRC panel to observe whether or not the models could predict the observed damage. Each of the LCFRC panels exhibited less material loss and less surface damage than the control panels. The addition of long carbon fibers significantly increased the concrete's blast resistance and significantly reduced the degree of cracking associated with the concrete panels. The results were also compared to the existing damage level chart in UFC 3-340-02.