Boliubash Ye.S. Improvement of the separation system of rocket-space elements using pyrotechnic devices. ‒ Qualifying scientific work as a manuscript Dissertation for the degree of Doctor of Philosophy in specialty 134 – Aviation and Space Rocket Engineering in the field of knowledge 13 – Mechanical Engineering. – Yuzhnoye State Design Office, Dnipro, 2025.
Amidst the growing volume of space launches and increasing competition in the space services market, particular attention is paid to reducing launch costs, decreasing the mass of rocket systems and spacecraft, and ensuring a high level of safety. In this context, separation systems play an important role, as they must be lightweight, effective, and reliable.
Among the separation systems used in rocket and space technology, the development of new, more effective and reliable systems is a relevant issue. Modern safety and environmental protection requirements impose stringent demands on the reliability of launch vehicles and the mitigation of consequences in emergency situations. In this regard, modern launch vehicles must be equipped with effective separation systems and safety systems. Linear shaped charges are promising executive elements in these systems: they are lightweight, effective, reliably cut the emergency launch vehicle into smaller fragments, and contribute to reducing the consequences of emergency situations.
The design of separation systems based on linear shaped charges is a complex task. The effectiveness of linear shaped charges, in particular the penetration depth of the cumulative jet, critically depends on a number of parameters, the key of which when using charges of a standardized series are the size (diameter) of the linear shaped charge and the stand-off distance. Deviations from the optimal (rational) stand-off distance lead to a decrease in the effectiveness of the linear shaped charge, which requires the use of charges of a larger size. This, in turn, leads to an increase in the structural mass, intensification of shock-wave loads, increase in cost, and overall decrease in system efficiency.
During flight, the launch vehicle is subjected to significant thermal and mechanical loads. Multilayer structures (barriers) are widely used to protect structural elements from high temperatures and aerodynamic effects, where the first (power) layer is metallic (e.g., made of alloy 2219), and subsequent layers consist of special protective coatings in the form of composite materials. When separating such barriers, the shaped charge jet penetration process is complicated by the sequential interaction of the jet with dissimilar materials, each having specific physical and mechanical characteristics and fracture peculiarities. Therefore, for optimizing structures and increasing their effectiveness, there is an urgent need to study the design parameters of the linear shaped charge specifically for such multilayer barriers typical for rocket and space technology.
In the dissertation work, a comprehensive analysis of the current state of executive elements of separation systems, particularly linear shaped charges with a semi-cylindrical cumulative liner, was conducted, which allowed identifying the main scientific and technical problems. Existing methodologies and mathematical models do not sufficiently accurately describe the process of formation and penetration of a shaped charge jet of a linear shaped charge, including those of domestic production with a semi-cylindrical cumulative liner, which complicates the optimization of these parameters.
Designing effective separation systems for rocket and space technology elements using linear shaped charges for separating multilayer barriers is a complex scientific and technical task. Determining the optimal design parameters of the executive element – size and stand-off distance – to ensure effective penetration into a multilayer barrier is conditioned by the dependence of this process on many factors, including the characteristics of the cumulative liner material and barrier layers, geometric dimensions of the shaped charge jet and cumulative liner, type and amount of explosive material, stand-off distance, as well as the technological level of linear shaped charge production.
Thus, designing effective separation systems by increasing the effectiveness of the separation system, achieved by determining the rational size of the linear shaped charge and the rational stand-off distance for cutting a multilayer barrier where the first layer is made of aluminum alloy grade 2219 and the next two layers are made of a composite multifunctional coating, is a relevant and timely scientific task.
