DESIGN AND ANALYSIS OF ADDITIONAL PROTECTIONS ON AN ARMORED VEHICLE TO COMPLY STRUCTURAL BLASTWORTHINESS

• Main Author: Nur Pratomo, Arief
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46454
• Institution: Institut Teknologi Bandung

Structural blastworthiness is an ability of a structure to deform in a controlled force and a preserved sufficient residual (survival) space around the occupants to minimize injury when a blast impact incident occurs. This phrase was proposed to show the urgency of the blastworthy structure that guaranteed the safety of the occupants due to mine threats that happened mostly in war-conflicted countries. Previous researches showed that an aluminum foam sandwich (AFS) had a superior blast energy absorption characteristic. The AFS is a construction of an aluminum foam (Al-foam) panel that is sandwiched between two metal plates. The unique characteristic of the Al-foam as the blast energy absorber can be observed through massive deformations in the cell walls of the foam air cavities when subjected to a compressive impact loading. The Al-foam is not only lightweight, but it also has a large strain/deformation energy capacity (the area below the stressstrain curve). Under compressive loading conditions, the Al-foam undergoes long plateau stress before densification occurred. Therefore, the Al-foam has better energy absorption per mass than other materials. The main objective of this research was to improve the blastworthiness of an armored vehicle (AV) called Anoa 6×6 from level 1 to level 3, referred to NATO STANAG 4569. The strategy to achieve this objective was to design and to analyze additional protections in the form of the AFS and an anti-mine seat that were applied to the AV. After additional protections were installed, the occupant safety was then analyzed in injury risk assessments. This dissertation focused on the effects of additional protections to the AV’s occupant safety against mine threats. The primary additional-protection that uses the AFS was installed under the vehicle’s floor to resist a mine threat. The mine threat in the form of 8 kg trinitrotoluene (TNT) was located under the vehicle’s belly (NATO STANAG 4569 level 3b). NATO STANAG 4569 and Allied Engineering Publication (AEP) 55 volume 2 were used as the standard. In general, the AFS still caused high acceleration and deformation on the AV’s floor during the mine explosion. The remaining acceleration and deformation were countered iii by the secondary additional-protection in the form of the anti-mine seat so that it can pass all the injury assessment reference values (IARV). This research consisted of three main activities: the structural integrity test, the occupant survivability test, and the occupant survivability test for overmatch condition. These three main activities were further divided into six stages according to the name of the chapter: (1) literature study, (2) numerical modeling for blastworthiness of AFS, (3) design and analysis of blast experiment setup of AFS, (4) experiment validation to evaluate the blastworthiness characteristic of AFS, (5) design and analysis of occupant survivability of the armored vehicle, and (6) design and analysis for robust design of additional protections of the armored vehicle. The results showed that the additional protections of the AV in the form of the AFS and the anti-mine seat complied with both NATO STANAG 4569 level 3b and AEP 55 volume 2. The AFS construction passed the structural integrity test that was indicated by the absence of cracks or holes after the explosion. However, the local acceleration and deformation on the AV’s floor were still high, about 30,114 G and 15 cm, respectively. Due to the remaining acceleration and deformation, the existing anti-mine seat was not able to pass the occupant survivability test, so some modification on the seat system was required. The modifications consisted of (1) changes in the seat installation system and (2) elevation of the footrest position. By using the modified anti-mine seat, the injury risk was reduced more than 90% in every critical body-part (head, neck, and tibia). On the overmatch test, the antimine seat must be modified further, so it was able to withstand a blast load of 10 kg TNT. The advanced modification by applying a higher footrest position (24 cm) was able to comply with the 10 kg TNT, but it probably made the occupants not comfortable. This research has a major impact on the military industry and the raw steel and aluminum industry. For the domestic military industry, there is an added-value for the commercialization of the AV with an anti-mine version. Moreover, the use of the AFS will drive the production of domestic companies. For instance, PT INALUM can provide the supply chain for the Al-foam needs, while PT Krakatau Steel can supply the high and medium strength steel that has so far been imported. The novelty of this research lies in the methodology, the additional protection products, and the numerical models used to evaluate the additional protections and its effect on the occupant safety in the AV against the mine threat.