PSI - Issue 72

Aria Pranata et al. / Procedia Structural Integrity 72 (2025) 383–391

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1. Introduction Patrol boats are essential for maintaining maritime security, enforcing laws, and conducting surveillance, particularly in areas prone to illegal activities and challenging environmental conditions (Prabowo et al., 2022; Rahmaji et al., 2022; Pratama et al., 2023; Lutfi et al., 2024; Yusfianda et al., 2024). However, operating in harsh marine environments exposes these vessels to significant risks of material degradation and structural failure (Huang et al., 2023). This challenge is evident in data from Indonesia’s National Transportation Safety Committee (KNKT), which recorded 171 maritime incidents between 2015 and 2022, with 40.35% involving sinking or grounding. These incidents highlight the urgent need for materials that are both durable and reliable under such demanding conditions (National Transportation Safety Committee, 2024). Fig. 1 shows the number of accident cases by incident type.

b

a

10 15 20 25 30 35 40 45

Number of Cases

0 5

2015 2016 2017 2018 2019 2020 2021 2022

Years

Total Incidents

Sinking Grounding

Fig. 1. (a) Graphic number of accidents by incident type; (b) Patrol boat accident (National Transportation Safety Committee, 2024).

One of the contributing factors to the high number of maritime accidents is material degradation, primarily due to corrosion and weaknesses in welding joints, which gradually reduce the structural strength of vessels. The sinking of MV Windu Karsa on June 19, 2011, in the waters of East Kalimantan is an example of an incident involving material degradation. Water entered the steering compartment, causing the vessel to lose buoyancy and ultimately sink. Investigations suggested that the leakage was likely caused by material failure or damage to joints that were either undetected or inadequately repaired. Factors such as corrosion and material fatigue were suspected to play a role, given the harsh operational conditions of the vessel (National Transportation Safety Committee, 2012). A similar case occurred with MV Dumai Express 10, which sank on November 22, 2009, in the Rupat Strait, Riau. The vessel sustained damage to its upper structure, exhibiting cracks likely caused by material fatigue or degradation resulting from exposure to the marine environment. These incidents illustrate how material degradation, including corrosion and joint failures, can be a primary cause of ship accidents. This highlights the importance of selecting materials that can prevent structural failures and mitigate the risks of such incidents. The use of corrosion-resistant materials, such as aluminum, that maintain structural integrity is a key solution for constructing patrol boats (National Transportation Safety Committee, 2010). Aluminum alloys are highly popular in the construction of patrol boats due to their advantageous properties, including being lightweight, offering excellent resistance to corrosion, and requiring less maintenance compared to traditional materials like steel (Saleh, 2020; Hosseinabadi and Khedmati, 2021; Petrović et al., 2021; Alwan et al., 2022; Ansori et al., 2022; Lazarević et al., 2023). These attributes enhance vessel speed, fuel effici ency, and operational lifespan. However, in long-term applications, aluminum alloys face critical challenges, particularly from two main factors: seawater corrosion and issues with welded joints (Feng et al., 2022; Safeen and Russo Spena, 2019). Seawater corrosion can lead to material degradation and structural weakening over time. Conversely, welding processes often introduce residual stresses and alter the alloy's microstructure, thereby reducing its overall strength and durability (Al-Fozan and Malik, 2008; Clara et al., 2023; Nugroho et al., 2023; Sudarno et al., 2023). This review aims to understand the extent to which aluminum alloys are affected by these degradation mechanisms. By examining existing research on corrosion and welding-related issues, this study aims to identify knowledge gaps and provide insights that can inform future innovations. The ultimate goal is to contribute to the development of more