فصلنامه پدافند غیرعامل
سال هفتم شماره 1 (پیاپی 25، بهار 1395)

Increasing terrorist attacks to substructure and transport structures is an alarm for national security. In the past designing structures against the explosive loads were only limited to military buildings and buildings related to atomic activities. Bridges are important elements in transport systems. The vital rule of bridges and national importance of them makes the bridges a good target as a terrorist attack. Better design of these structures under explosive load to prevent growing collapse is of great importance. Prestressed concrete bridges are very popular however; there is lack of information and study about these bridges under the explosive load.
In this research a finite element model for concrete bridges with prestressed elements has been established by ABAQUS software. A validation has been carried out by laboratory test of other researchers and acceptable convergence was observed.
Established models were placed on the width of bridge deck under different explosive scenarios by different weight of explosive materials. Collapse process of bridge has been observed and the destruction mechanism has also been investigated. Results of this study give us some information about behavior and possible response of pre prepared bridges under the severe explosive load which can help the engineers to select the most effective way of operation improvement and retrofitting of these bridges.

Traffic jam in big cities has prompted using underground metro trains more than ever. Train moving along railway is causing noise and vibrations. The generated vibrations cause damage to nearby people and buildings. In this study the effects of noise and vibration of Qom metro train into entrance of Ghiyasieh Madrasseh are studied. Thus, primarily partial velocity is calculated, according to the location of this building to the lining, and then in compare with the comparative method with index of USA (FTA VA90 1003 06) and other references, the effects of vibrations on this structure are evaluated. Consequently the results showed that Qom metro lining has in considerable effects on entrance of Ghiyasieh Madrasseh. Nonetheless, there are proposed some approaches, such as reducing trains speed and transfer generated vibrations through railways, for mitigating probable damages to this historic structure .

The main objective of this paper is solving the problem of voltage variations of Hybrid Photovoltaic/Fuel cell at different conditions. Because of valuable advantages of hybrid DG power systems, using from these power systems become more and more prevalent. But there are some defects that cause the application of DG power system unacceptable. One of these deficiencies relates to the malfunction of energy sources. For example, during shaded conditions the output power of PV arrays reduces to negligible values or by stopping the correct electrochemical process of fuel cell, it cannot deliver power to the grid. The other problem of Hybrid Photovoltaic/ Fuel cell is that there is not enough reactive power for delivering to the load and this cause the voltage reduction of DG power system. To solve mentioned problems, in this survey, it is suggested that by applying SMES system and DSTATCOM, active and reactive power can be provided to the load, respectively. But, adding these elements to the power system at the same time needs to an efficient controller. In this paper, multivariable control strategy as an efficient method which can regulate the voltage of the DG power system busses with an appropriate dynamic is selected to design the controller. Generally, in this paper, after designing one standard Hybrid PV/Fuel cell DG power system, by adding the elements of SMES system and DSTATCOM, the voltage of the proposed system is regulated at different conditions and this fact is approved via simulation tests.

Graphite bomb is a non destructive weapon that its aim is about disturbing electrical power supply and blackouts. In this paper, a new method for categorizing power system substations is proposed where the comparing parameter is system response to graphite attack and substation outage. Power system substations take different roles in system, thus, their response to attack should be different. Substations outage in response to attack has different impact on system response. In some cases, bus outage cause no influential difference, while in extreme cases its outage may cause real time system collapse. Therefore, studying power system reaction to substation outage is necessary for providing and designing proper special protection scheme. In this paper, the main route of categorizing and different groups are explored thorough simulation on standard test cases.

Proper protective clothing is needed during every day in industrial, agricultural, medical work, during military operation and response to terrorism incident. Choices must be made as to which items of protective clothing to select for a given situation or environment. A number of variable to be consider ed include weight, comfort, level of protection and during of protection required. The protective clothing used in the World War I against chemical warfare agents (CWA) consisted of rubber clothing, which, together with gloves and boots, to cover the entire body apart from that protected by the mask. Clothing of this kind is usually characterized as impermeable. This means that CW agents cannot pass through the material and also the fact that perspiration released from the skin is also prevented from passing out. onsequently, to wear clothing of this kind for longer periods is extremely uncomfortable and in hot climates the period during which protective clothing of this kind can be worn will be very short. This review brings out a sequence related to the NBC protective clothing, their type, various materials available for the development of NBC clothing. An ideal protective cloth is the one that resists encountering with dangerous gases and steams. Another word, an ideal protective cloth is the one that has pregnability facing with water steam and low impregnability encountering with different gases. In other to produce the above protective clothing, it is suitable to use polymeric membrane. The customary NBC clothing is based on foam thus is saturated with active carbon. A substantial portion of active carbon is contact to the foam which is not participated in absorption process. Carbon fiber demonstrates good physical stability and it can be used in NBC clothing instead of foam. All surface of carbon fiber participates in absorption of chemical agents. Simultaneous application of polymeric membranes and carbon fiber conforms and produce a clothing with high safety and high durability in contamination area.

This paper evaluates the safety of civil defense and its necessity in Semnan city of approach and aims to reduce the vulnerability of human resources and buildings and critical facilities and the city of Semnan in the event of a possible enemy threat and the continuation of activities and services under Office Building and the needs of city life and the continuation of the crisis caused by the war. To achieve this objective weighting method AHP TOPSIS technique is used to prioritize and control. views and observations and spatial analysis, appropriate strategies, in order to achieve the safety of vital centers, critical qualitative and quantitative development Semnan and recognizing the limitations of passive defense and settlement structure was presented in Semnan.

In this paper the reactive powder concrete (RPC) behavior subjected to different explosion charges and also in different distance of explosion point has been investigated. Moreover, the effect of change in the thickness of RPC slab has been considered. In order to analytical simulation of RPC behavior against blast and also accuracy of results using ABAQUS software, a RPC slab studied in the literature has been verified. The obtained results are showed that the simulated model of RPC is match with literature one. In order to compare of resulted results of RPC slab a NSC slab has also simulated. Different scenarios of explosion in form of tow numerical examples have been considered. It’s noted that the NSC slab is supposed to be a reinforced concrete, whereas 2% volume of special short steel fibers were used in the RPC specimen. The acquired results of analysis have been showed that the RPC have better blast explosion resistance than reinforced normal strength concrete and can be used in built and strengthening of structures.