The main aim of the work was the experimental and numerical analysis of the energy absorption/dissipation capabilities and failure mechanisms of novel hyper-elastic target material intended for ballistic applications including layers of composite armors, projectile catching systems and anti-ricochet layers covering walls of shooting ranges, ballistic tunnels, etc. Static and dynamic mechanical properties of the material were analyzed at both room and elevated temperatures ( $$40\div 80\,^{\circ }\hbox {C}$$40 ÷ 80 ∘ C ). Numerical models of the material and $$7.62\times 25$$7.62 × 25 mm FMJ projectile were defined. Simulations of the hyper-elastic target penetration with the projectile were carried out. The differences between the results obtained numerically and experimentally were determined (measured as a relative error) and were lower than 15% what testified about proper definition of the numerical models of the analyzed phenomenon components.

Three types of barrel steel, i.e. 38HMJ, 30HN2MFA, and DUPLEX, were used for investigations of temperature characteristics of thermal diffusivity and thermal expansion in the temperature range from 50°C to 1000°C. The tests were carried out applying the Netzsch laser flash apparatus LFA 427 and the Netzsch dilatometer DIL 402 C. The results of the thermal expansion tests revealed that in steels 38HMJ and 30HN2MFA a material shrinkage occurs in the temperature range of 730-740°C. This effect does not occur in DUPLEX steel. The barrel of the rifle is covered with a layer of galvanic chromium. Contraction of the substrate leads to cracking of the protective layer of chromium. The cracking effect of the chromium layer can be caused by passing ferrite to austenite at 730°C. The results of thermal diffusivity investigations of tested materials confirmed phase transition effect only in the steels 38HMJ and 30HN2MFA. Taking into account that in DUPLEX steel material shrinkage in the tested temperature range does not occur, for that reason, this material is considered when designing the barrels of modern rifles.

The article presents dynamic mechanical analysis (DMA) for solid rocket propellants testing. Principles of operation and measured values are briefly described. The authors refer to the previous research of PTFE material and literature data providing information about proper experimental conditions and influence of measurement frequency, load amplitude, and heating rate on the results of DMA tests. The experimental results of solid double-base rocket propellant testing obtained on the N Netzsch DMA 242 device are presented. Mechanical properties such as the dynamic storage modulus E´, the dynamic loss modulus E˝ and tan(δ) were measured within temperature range from (–120°C) to (+90°C) at the heating rate of 1 K/min. The test sample was subjected to a dual cantilever multi-frequency test. Special attention was paid to determination of the glass transition temperature of the tested propellant in reference to the NATO standardization agreement 4540 as well as influence of the measurement frequency on the glass transition.[b]Keywords[/b]: Dynamic mechanical analysis, solid rocket propellants, glass transition temperatur

In this paper the results of storage modulus (E’), loss modulus (E’’) and damping parameter tan (δ)=E''/E' of epoxy resins Epidian 57 and L285 with curing agents Z1 and LH285, respectively are presented. In addition to this the stress-strain and thermal expansion characteristics of Epidian 53, 57 and L285 were obtained experimentally in order to compare Dynamic Mechanical Analysis (DMA) results. Temperature range of DMA investigations using Netzsch (Germany) DMA 242C analyzer was from-120 °C to +110 °C at the heating rate of 1 K/min with frequency of {0.1, 1, 10} Hz, respectively. Netzsch DIL 402C dilatometer was used to study the thermal expansion of the tested samples within temperature range from 30 °C to 80 °C at 1 K/min of heating and cooling rates, respectively and Huang TA computer servo control material testing machine HT-2402 was applied to determine the stress-strain characteristics. Measurements of sample elongation ΔL and physical α* were performed twice in heating and cooling cycles. The glass transition temperature T_g determined from maximum of tan (δ) curve at f = 1Hz was equal to 76.7 °C for E57 and 87.2 °C for L285. It has been observed durable deformed shape of L285 sample with deflection in the middle about 5 mm just after finishing the DMA first run of heating which significantly affected DMA results during the second run of heating

The effectiveness of multi-barrel rocket systems on today’s battlefields is strongly dependent on the reliability of operation and, hence, proper action of all components, especially rockets and propellants. Therefore, the properties of the solid rocket propellants used in the rocket motors must be determined with an efficient and reliable tool providing repeatable results. The article presents the results of a thermomechanical analysis of solid double-base rocket propellant used in multi-barrel rocket systems. One of the recommended methods for testing solid rocket propellants is dynamic mechanical analysis. Mechanical properties such as the dynamic storage modulus $$(E^\prime )$$( E ′ ) , the dynamic loss modulus $$(E^{\prime \prime }),$$( E ″ ) , and the tangent tan $$(\delta )$$( δ ) of the phase shift angle $$(E^{\prime \prime }/E^\prime )$$( E ″ / E ′ ) were measured with the use of the TA Instruments DMA Q 800 device, in a temperature range of − 100 to $$+$$+ 100 $$^\circ $$∘ C with the use of different frequencies of applied force and heating rates. Special attention was devoted to determining the glass transition temperature following the STANAG 4540 standardization agreement, as well as the influence of testing parameters on the obtained experimental results. Dynamic mechanical analysis has proven to be an effective method for the evaluation of key properties influencing rocket motor behavior.