الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 189 |  |  |
| | | from | 189 | | |
Abstract
This research has presented a numerical study for evaluating the behaviour of the RC Curved and T-Shaped fences against blast loads and improving their blast resistance capacity. This analysis was carried out using the commercial program LS-DYNA which is a general-purpose finite element code for analysing the large deformation dynamic response of structures.
The results were evaluated according to the damage and the value of the deformation. Validation has been performed by comparing FE modelling numerical results of a RC fence under blast detonations with available blasting experimental work in literature.
RC fences with two different shapes (Curved and T-Shaped) using Normal Strength Concrete (NSC) have been examined against explosive charges. The influence of using Ultra-High-Performance Concrete (UHPC) and CFRP sheets for improving the blast resistance capacity has been investigated.
Comparisons of the damage of the RC fences due to the blast waves have been conducted to study the effect of using shear connectors to resist the overturning moment and to study the effect of using CFRP sheets on all sides versus using it on front and back sides only.
6.2 Conclusions
from the study carried out through the present research, the following points can be recorded:
1- A comparison of the experimental results of a RC fence conducted by Pantelides et al.17 and the FE modelling results show that a great agreement between the FE analysis results and the test results. The difference between the experimental test and the FE analysis results is 0.428%. The developed FE model accurately predicted the deflection and damage against blast loads.
2- The behaviour of the RC T-shaped fences against blast loads are much better than the behaviour of the RC Curved fences, because of the little damage and the low generation of the debris and fragments under the same quantity of blast with specified distance:
- The surface of the RC Curved fence collect and concentrate the blast wave in the curved shape and immediately cause big significant damage to the curved surface.
- The surface of straight RC T-Shaped fence doesn`t collect and concentrate the blast wave and therefore have less damage compared with the curved surface.
3- The usage of Ultra-High Performance Concrete or the externally bonded CFRP sheets significantly improves the blast resistance capacity of the RC fences. Little damage and the low generation of the debris and fragments compared with the using of Normal Strength Concrete (NSC) only.
4- from the results of the FE modelling, the RC fences have exposed to high overturning moment, which requires increasing the thickness of the RC fence. In addition, the use of RC fence with RC footing with an appropriate width may increase the factor of safety against the overturning moment.
5- Using shear connectors at the base of the RC fences have a significant effect on the behaviour of the RC fences against blast loads. The use of shear connectors improves their blast resistance capacity.
6- The behaviour of the RC fences strengthened with CFRP in all sides against blast loads is better than strengthened with CFRP on the front and back sides of the fence. It`s observed that the fence strengthened with CFRP in all sides has less damage in the reinforced concrete parts.
7- from the comparison between the results of LS-DYNA and SPEC-905 Code for the RC Curved and T-Shaped fences with charge 25 Kg TNT, The results obtained from SPEC-905 Code are generally conservative with respect to the FE results for each fence type.