长期贮存的固体发动机药柱脱粘界面裂纹分析

为了分析长期贮存的固体导弹发动机药柱脱粘层界面裂纹在燃气内压和轴向过载联合作用下的扩展情况,建立了发动机药柱在包覆层与推进剂之间脱粘的三维有限元计算模型,并于脱粘界面的裂纹尖端设置三维奇异裂纹元,模拟脱粘界面裂纹扩展。在包覆层与推进剂之间设置不同深度脱粘,计算了在燃气内压和轴向过载联合作用下不同贮存期、不同深度的界面裂纹尖端的应力强度因子,得到了界面裂纹应力强度因子随贮存时间、脱粘深度的变化规律,对长期贮存的固体发动机脱粘界面裂纹的扩展进行了分析。     

Acrimony,asymmetry, and the Sino-Indian nuclear relationship

ABSTRACT

While most contemporary analyses of South Asian nuclear dynamics acknowledge the presence of a strategic triangle between the region’s three nuclear players, the primary focus usually remains on the rivalry between India and Pakistan. Discussions of Sino-Indian relations remain limited. This is likely attributed to the stability in the two countries’ relations, yet it is worth asking why this stability exists and whether it is likely to continue in the future. Although China and India have an acrimonious relationship, their asymmetric nuclear capabilities and threat perceptions mitigate the danger of a traditional security dilemma. India may perceive China’s nuclear aggrandizement to be a security threat, but the same is not true of China, which has a vastly superior nuclear force and is largely shaping its nuclear-force structure in response to the threat it perceives from the United States. This dynamic makes a serious conventional or nuclear conflict highly unlikely.     

Defence industry in Iran – between needs and real capabilities

ABSTRACT

The paper’s goal is to analyses the potential of the Iranian defence industry, including both research-and-development and production capabilities. It is argued that, despite official statements about the great power and sophistication of the Iranian defence industry, in reality its capabilities are very limited and cannot meet the operational needs of the Iranian armed forces. At the same time, it is argued that many official releases, which are abundantly available in the Iranian press and often unthinkingly repeated by the Western media, do not present the real and value of military products, but are rather a tool for deception and propaganda.     

United States defence contractors and the future of military operations

ABSTRACT

The United States’ global strategic outlook has shifted markedly since the end of major combat operations in Iraq and Afghanistan. As the United States’ strategic posture shifts, the nature of military operations is simultaneously changing rapidly. Many analysts predict that cyber-operations, autonomous weapons systems, artificial intelligence, and clandestine special forces operations will be central features in future conflicts. Although often overlooked by scholars and policy analysts, defence contractors are integral to the development and implementation of these emerging categories of warfare. This inquiry examines the evolving nature of the American defence industry and the roles corporations play in current theatres of conflict. Surprisingly, rather than becoming less reliant on defence contractors after their much-maligned performance in the wars in Iraq and Afghanistan, American military and intelligence agencies have become more dependent on the private sector as technology becomes increasingly central to warfare.     

Building the Somali National Army: Anatomy of a failure, 2008–2018

ABSTRACT

Over a decade of security force assistance (SFA) initiatives to build an effective Somali National Army (SNA) failed because of the interrelated effects of political, contextual and operational challenges. The key political challenges were interest asymmetry between international actors and Somali elites, insufficient focus on institution-building and a lack of donor coordination. The principal contextual challenges in Somalia were the legacies of two decades of state collapse and the negative effects of clan dynamics. The main operational challenges were building an army while simultaneously fighting a war, the complexities of military integration, and the severe capability gaps afflicting the SNA.     

Glimpse into an army at its peak: notes on the Somali National Army in the 1960–80s

ABSTRACT

Bagayoko, Hutchful, and Luckham correctly argue that the structures, characteristics, and operating methods of official security institutions in Africa have been somewhat neglected, with a lack of much recent research. The Somali National Army (SNA) sits among these lacunae. Its formal structures can be used as a skeletal starting point and springboard to start to draw the network diagrams that chart informal linkages. This is why recent declassification decisions by U.S. intelligence bodies, coupled with period documents released to the UK National Archives, hold significance in helping us understand early hierarchical SNA arrangements. They show the steady build-up in size of the force, to 1987, to about the time the civil war began to fragment the state.     

Nigerian women and the trends of kidnapping in the era of Boko Haram insurgency: patterns and evolution

ABSTRACT

The rising trend of kidnapping targeting women has shown that counterinsurgency does not begin and end with the strategic advantage of state security providers in the security market and the field. Kidnapping of females by Boko Haram insurgents threatens human security and hinders sustainable development goals in Northeastern Nigeria. With primary and secondary sources, this qualitative study examines how Boko Haram insurgents target women in Northeastern Nigeria. The paper argues that community driven security strategy achievable through the collaboration between state and traditional security providers, can prevent the entry and easy escape of the insurgents. It concludes that the forces of order should sustain a policy of stop and searches until insurgents are defeated along with a programme of community-based human rights education and insurgency emergency response system for quick response to security threats.