Split Hopkinson Pressure Bar Research Articles

Signal Correction for the Split-Hopkinson Bar Testing of Soft Materials

The Split-Hopkinson pressure bar (SHPB) test is a commonly accepted experiment to investigate the material behavior under high strain rates. Due to the low impedance of soft materials, here, the test has to be performed with plastic bars instead of metal bars. Such plastic bars have a certain viscosity and require a correction of the measured signals to account for the attenuation and dispersion of the transmitted waves. This paper presents a signal correction method based on a spectral decomposition of the strain-wave signals using Fast Fourier Transform and additional applied strain gauges in the experimental setup. The concept can be used to adapt the pulses and to concurrently validate the measurement method, which supports the evaluation of the experiment. Our investigation is carried out with a Split-Hopkinson pressure bar setup of PMMA bars and silicon-like specimens produced by the 3D printing process of digital light processing.

Longitudinal wave propagation determination in concrete specimen under impact loading by ultrahigh-speed camera image sequence and strain gauge data analysis

Abstract To demonstrate the potential of an ultrahigh-speed camera with frame rates beyond a million images per second for high dynamic material analysis, cylindrical concrete specimens are tested under compression at strain rates up to 164.3 s-1 in a split Hopkinson pressure bar facility. The evaluation includes the determination of the actual longitudinal wave propagation velocity and the induced longitudinal deformations. The results obtained from image sequence analysis are validated with those obtained by the well-established strain gauge measuring technique that estimate the specimen deformation in the same facility. Data analysis for both measuring techniques is based on the one-dimensional wave theory. Image quality challenges affecting the material analysis are overcome by applying a Bézier fitting filter to the image sequences. Using the image-sequence-based approach to select stress-wave-induced motion points, different wave characteristics are acquired. Subsequently, selecting the points in compression during the first stress wave transit yields longitudinal wave propagation velocities up to 2995 m/s with a standard deviation of 265 m/s. From the validation results, first, an observed bilateral complementarity of both techniques enables a comprehensive analysis of the specimen deformation. Second, individual discrepancies between the material properties obtained from both techniques up to ultimate compressive strength for deformation, velocity, strain, and stress of 20.8 %, 14.4 %, 8.3 %, and 10.0 %, respectively, are achieved.

Dynamic behavior of a running crack crossing mortar-granite interface with different interface inclinations

High-strength mortar is widely applied in fractured rock reinforcement due to its strong bonding strength, where crack propagation crossing the interface is commonly seen. To investigate the dynamic crack propagation behavior across the interface, A side material cleavage triangle (SMCT) sample was adopted in this study with different interface inclinations and mortar strength considered. Impact testing of a split Hopkinson pressure bar (SHPB) system was conducted and cohesive models were established to explore the penetration process of the extending crack. With the numerical result and the measurement of the crack propagation gauges (CPGs), the dynamic stress intensity factor (DSIF) was determined using an experiment-based numerical method. The investigation results show that the excited crack always propagates across the mortar-granite interface regardless of the stiffness difference, and this phenomenon remains unchanged with increasing interface inclination. For SMCT specimens, as the strength grade of mortar increases, the time taken for cracks to propagate through the interface increases. As the interfacial inclination increases, the time taken during crack penetration through the interface is longer. Using Python coding, cohesive elements can be embedded in batches in the numerical model to simulate crack propagation behavior at the interface. As the interface inclination increases, the DSIF in both the mortar and granite regions exhibits an upward trend.

Impact energy release characteristics and penetration behavior of high-density VNbTa medium-entropy alloys

This study systematically investigated the dynamic mechanical properties and penetration-damage behavior of high-density VNbTa medium-entropy alloys under dynamic loading. The split Hopkinson bar, impact energy release, and spaced-target plate tests were carried out. Results from the impact energy release test indicated that a significant chemical reaction and substantial energy release occurred when the alloy hit a rigid target plate at high speed. The spaced-target plate penetration test verified the combined destructive effect of the alloy’s kinetic and chemical energies during penetration, leading to large perforations and severe deformation of the rear target plate. Moreover, a shock-induced energy release model and a fragment cloud diffusion model were established, uncovering the energy release mechanism and fragment-cloud expansion law. These findings provide a theoretical and experimental basis for the design and application of high-density, high-energy structural materials.

Structural Effects on Compressive Strength Enhancement of Cellular Concrete During the Split Hopkinson Pressure Bar Test

In recent years, a kind of novel cellular concrete, fabricated by spherical saturated superabsorbent polymers, was developed. Its compressive behavior under high strain rate loadings has been studied by split Hopkinson pressure bar equipment in previous research, which revealed an obvious strain rate effect. It has been found by many researchers that the dynamic increase factor (DIF) of compressive strength for concrete-like materials measured by SHPB includes considerable structural effects, which cannot be considered as a genuine strain rate effect. Based on the extended Drucker–Prager model in Abaqus, this paper uses numerical SHPB tests to investigate structural effects in dynamic compression for this novel cellular concrete. It is found that the increment in compressive strength caused by lateral inertia confinement decreases from 5.9 MPa for a specimen with a porosity of 10% to 2 MPa for a specimen with a porosity of 40% at a strain rate level of 70/s, while the same decreasing trend was found at other strain rate levels of 100/s and 140/s. The lateral inertia confinement effect inside the cellular concrete specimen can be divided into the elastic development stage and plastic development stage, bounded by the moment dynamic stress equilibrium is achieved. The results obtained in this research can help to obtain a better understanding of the enhancement mechanism of the compressive strength of cellular concrete.

Mechanical Properties and Constitutive Model of High-Mass-Fraction Pressed Tungsten Powder/Polytetrafluoroethylene-Based Composites

Heavy metal powders driven by explosions can enhance the near-field lethality of explosive warheads by forming a quasi-pressure field while reducing collateral damage at medium and long ranges. Incorporating polymers into high-content metal powders prevents powder sintering under explosive high pressure, enhancing dispersion uniformity and making them promising for controllable warhead applications. To describe the mechanical behavior of materials under impact loading, this paper investigates the dynamic and static mechanical properties and constitutive modeling of tungsten powder/polytetrafluoroethylene (PTFE) composites. Quasi-static compression tests and split Hopkinson pressure bar (SHPB) dynamic tests were conducted on composites with varying tungsten contents (0 wt%, 70 wt%, 80 wt%, and 90 wt%) and particle sizes (200 μm, 400 μm, and 600 μm), obtaining compressive stress–strain curves over a strain rate range of 0.001 to 3610 s−1. The compressive strength of the composites slightly decreased with increasing tungsten particle size but increased with higher tungsten content. Under quasi-static compression, the compressive strength of the composites with 70 wt% and 80 wt% tungsten was lower than that of pure PTFE. This was due to the bonding strength between the tungsten particles and the resin being weaker than the cohesion within the resin. Additionally, the random distribution of the tungsten particles in the matrix led to shear cracks propagating along the phase interfaces, reducing the compressive strength. The compressive strength of the composites with 90 wt% tungsten exceeded that of pure PTFE, as the packed arrangement of the tungsten particles increased the material strength through particle extrusion and friction during compression. Under dynamic impact, the compressive strength of the composites was higher than that of pure PTFE, primarily due to particle extrusion and friction effects. The composites exhibited significant strain rate sensitivity, with both the compressive strength and critical strain increasing quasi-linearly with the strain rate. Based on the experimental data, a damage-modified Zhu–Wang–Tang (ZWT) viscoelastic model was employed to fit the data, effectively characterizing the uniaxial compressive constitutive behavior of tungsten powder/PTFE composites.

Dynamic Failure Mechanism and Fractal Features of Fractured Rocks Under Quasi-Triaxial Static Pressures and Repeated Impact Loading

Mastering the dynamic mechanical behaviors of pre-stressed fractured rocks under repeated impact loads is crucial for safety management in rock engineering. To achieve this, repeated impact loading experiments were performed on produced fractured samples exposed to varying pre-applied axial and confining pressures using a split Hopkinson pressure bar test system in combination with a nuclear magnetic resonance imaging system, and the dynamic failure mechanism and fractal features were investigated. The results indicate that the dynamic stress–strain curves exemplify typical class II curves, and the strain rebound progressively diminishes with growing impact times. The impact times, axial pressure, and confining pressure all significantly affect the dynamic peak strength, average dynamic strength, dynamic deformation modulus, average dynamic deformation modulus, maximum strain, and impact resistance performance. Moreover, under low confining pressures, numerous shear cracks and tensile cracks develop, which are interconnected and converge to form large-scale macroscopic fracture surfaces. In contrast, specimens under a high confining pressure primarily experience tensile failure, accompanied by localized small-scale shear failure. Under low axial pressure, some shear cracks and tensile cracks emerge, while at high axial pressure, anti-wing cracks and secondary coplanar cracks occur, characterized predominantly by shear failure. In addition, as the confining pressure grows from 8 to 20 MPa, the fractal dimensions are 2.44, 2.32, 2.23, and 2.12, respectively. When the axial pressures are 8, 14, and 20 MPa, the fractal dimensions are 2.44, 2.46, and 2.52, respectively. Overall, the degree of fragmentation of the sample decreases with growing confining pressure and grows with rising axial pressure.

Investigation on the mechanical responses of shallow coral reef limestones under dynamic loads

Coral reef limestone (CRL) is found only in ocean reef islands. Deepening the investigation of the dynamic performances of CRL helps expand its utilization in reef engineering. This study studied the dynamic response of shallow weakly-cemented CRL (WCRL) using experimental and numerical methods. First, the impact performance of the WCRL was tested using the Split Hopkinson Pressure Bar apparatus. The dynamic peak stress and peak strain of WCRL exhibited rate-sensitivity. Subsequently, the impact process of the WCRL was calculated in the numerical software LS_DYNA, with key dynamic parameters of WCRL calibrated based on the Holmquist-Johnson-Cook (HJC) model for the first time. The accuracy of the numerical results was verified with the experimental results. Thereafter, the dynamic failure process and energy dissipation mechanism of the WCRL were numerically investigated. As the strain rate increased, the failure of the WCRL specimens intensified. The energy analysis demonstrated that the destruction of WCRL specimens consumed more energy at high strain rates, though the distribution proportion of energy was rate-independent. Finally, the sensitivity analysis revealed that the certain parameters (A, B, C, N, p c, and μc) of the HJC model played a crucial role in describing the material’s dynamic response.

An Open-Source Algorithm for Correcting Stress Wave Dispersion in Split-Hopkinson Pressure Bar Experiments.

Stress wave dispersion can result in the loss or distortion of critical high-frequency data during high-strain-rate material tests or blast loading experiments. The purpose of this work is to demonstrate the benefits of correcting stress wave dispersion in split-Hopkinson pressure bar experiments under various testing situations. To do this, an innovative computational algorithm, SHPB_Processing.py, is created. Following the operational run through of SHPB_Processing.py's capabilities, it is used to process test data acquired from split-Hopkinson pressure bar tests on aluminium, sand and kaolin clay samples, under various testing conditions. When comparing dispersion corrected and simple time shifting data obtained from SHPB experiments, accounting for dispersion removes spurious oscillations and improves the inferred measurement at the front of the specimen. The precision of the stress and strain results gathered from its application emphasises its importance through the striking contrast between its application and omission. This has a significant impact on the validity, accuracy and quality of the results. As a result, in the future, this tool can be utilised for any strain rate testing situation with cylindrical bars that necessitates dispersion correction, confinement, or stress equilibrium analysis.

Dynamic fracture toughness and fractal characteristics of crack in pressurized acidified Qinshui coal under impact loading

To investigate the effect of acid fracturing fluid on the fracture toughness and fractal properties of crack propagation in Qinshui coal under impact load, the 50 mm diameter split Hopkinson pressure bar device was employed to carry out mode I dynamic fracture toughness tests on Qinshui anthracite samples treated with acid fracturing fluid and water-based fracturing fluid under different impact pressures. Coal samples were subjected to force saturation and acidity treatment using an innovative apparatus. The fracture propagation phase of the specimen was acquired by a high-speed camera sensor. Combined with Image J analysis software and PCAS image recognition system, the macroscopic crack propagation trajectory and probability entropy of micro pores in coal samples were quantitatively analyzed. These findings revealed that dynamic fracture toughness endowed a strong rate-response relationship. When the impact pressure is 0.3, 0.4, and 0.5 MPa, the average fracture toughness of the water-based fracturing fluid group coal specimens was respectively 0.64, 1.20, and 1.31 times better that of the acidic fracturing fluid group. The rate of crack propagation and the dynamic fracture toughness of coal were reduced after acidification of the specimens. The crack growth rate initially surged, then decreased rapidly until it reached a stable state under impact load, while the variation in crack growth length and opening breadth showed a time-dependent increase. Crack propagation resistance and dynamic fracture toughness of coal are reduced by the acidification of the specimens. The fractal dimension of cracks in specimen increased under the impact of pressure growth. The fractal dimensions of crack in coal samples under the action of acidic fracturing fluid at 0.30, 0.40, and 0.50 MPa are 1.066, 1.078, and 1.087 times that of water-based fracturing fluid, as well as 1.119, 1.136, and 1.157 times that of natural state coal samples. With the increase in impact pressure, the entropy magnitude of the pore probability on the fracture surface of the coal sample also increased. The fracture surface morphology of coal sample transformed from compact and neat to loose and porous with the action of acidification. The dual mechanism of weakening and enhancing the fracture behavior of anthracite coal by fracturing fluid under different loading rates was explored, and a microscopic fracture mechanics model incorporating loading rate was developed based on the dual nature of the fracturing fluid and linear elastic fracture mechanics theory. The study results offer empirical evidence to investigate the process of fracture initiation and propagation in acid fracturing in Qinshui coal, and provide theoretical direction for designing acid fracturing in coal seams and controlling complicated fracture network.

Achieving improved dynamic mechanical properties in twinning-dominated titanium alloys

Structural materials with low densities and high-strain-rate properties are of significant importance for the armor applications. Titanium and titanium alloys offer great potential in this regard but typically suffer from localized instability deformation during dynamic loadings. Here, we show that enhanced dynamic mechanical properties are attained in a twinning-dominated titanium alloy Ti-15Mo during split Hopkinson pressure bar tests. Under these tests, the solution treated specimens exhibit superior strain hardening capabilities compared to those of the solution treated plus aging specimens. Benefiting from this, the formation of the adiabatic shear bands (ASBs) and the subsequent material failure are delayed. The deformation-producing heat calculation suggests that the temperature rise is not a major origin of the adiabatic shearing. Yet, the strain localization associated with the non-uniform plastic deformation accounts for more. Microstructural characterizations indicate that the {332}<113> twinning, acting as a predominant deformation mode, improves the strain hardening capabilities of the Ti-15Mo alloy. With the increased strain rate, the increasing trend of the twin density gradually decreases, resulting in the grain boundary separations or even the formation of the ASBs at 4060 /s. The ASB’s shear zone has a density of dynamically recrystallized β grains with maximal hardness but poor strain hardening capability, while the adjacent transition zone experiences a highly localized shear deformation accompanied by the ASB widening. On the basis of these results, the impacts of the twinning on the microstructures and mechanical properties of the Ti-15Mo/Ti-15Mo laminated target plates after penetration experiments are discussed. We believe that titanium alloys with distinguished twinning effect can inspire their widespread applications in military fields.

Generating a twin-incident pulse for split Hopkinson pressure bar experiments

Generating a twin-incident pulse for split Hopkinson pressure bar experiments

Influence of Strain Rate and Temperature on the Multiaxial Failure Stress Locus of a Polyamide Syntactic Foam

This study introduces a comprehensive experimental methodology allowing for the direct measurement of the rate dependent multiaxial response of polymer syntactic foams under combined direct-shear loading. The combined tension-torsion behaviour of a syntactic foam and its rate dependence are investigated for the first time.Dynamic tension-torsion experiments were conducted using a newly developed Tension-Torsion Hopkinson Bar (TTHB) enabling the measurement of the combined tensile-shear response of engineering materials at high rates of strain.The response and multiaxial failure envelope of a polyamide syntactic foam were experimentally measured and analysed to determine the combined influences of stress state, strain rate, and temperature. The multiaxial failure stress locus was defined in both the normal versus shear stress space and the principal stress space, providing a comprehensive characterisation of the behaviour of the material under various loading and environmental conditions.The suitability of existing pressure dependent failure criteria to represent the measured experimental data was also assessed. The Drucker-Prager pressure dependent criterion proved to be effective in capturing the measured quasi-static and dynamic multi-axial stress loci at different temperatures.The effects of temperature, loading rate and stress state on the deformation and failure modes were analysed by means of SEM micrographs of the tested samples.

In situ characterisation of dynamic fracture in Al2O3 using ultra-fast X-ray phase contrast radioscopy: effects of porosity and crack speed

The dynamic fracture properties of porous ceramics were studied using single bunch synchrotron X-ray phase contrast imaging. The modified brazilian geometry was used to initiate and propagate a pure mode I crack. The specimen was compressed using the Split Hopkinson bars at strain rates of the order of 102 s-1. Main cracks were isolated for four different grades of Al2O3, one dense alumina, and three porous grades with 20% to 60% porosity. The maximum measured crack velocities for three grades is of the order of 0.6cR and 0.4cR for the most porous. The fracture energy was estimated using a FE numerical simulation to quantify the influence of inertial effects induced by crack propagation. The results show that these inertial effects are far from negligible (up to 80% of the stored energy) and that the dynamic correction factors known from the literature tend to overestimate the fracture energy. The values obtained vary from 22 J/m2 for the densest to 5 J/m2 for the most porous.

Experimental Study on the Dynamic Impact Characteristics of Iron Ore Under Free-Fall Conditions

Ore processing equipment is constantly subjected to impacts from various types of ore. However, the impact force characteristics generated by ore particles of different masses have not been thoroughly studied, which has hindered the design and monitoring of such equipment. This paper presents an experimental study on the dynamic impact characteristics of iron ore particles under free–fall conditions. The research focuses on understanding the mechanical behavior of ore particles of varying sizes and weights when colliding with metallic components, particularly crushers, which are critical in the ore processing industry. A modified Split Hopkinson Pressure Bar apparatus was utilized to measure the impact forces, durations, and deformation patterns during collisions. Two types of fired iron ore pellets were collected from industrial plants and sorted into different mass ranges for testing. The pellets were dropped from a height of 1 m to impact a steel rod, and the resulting impact forces were recorded using strain gauges. Additionally, finite element simulations were conducted to validate the experimental methodology. The results revealed significant variations in impact force, duration, and deformation patterns, influenced by particle mass and impact position. The maximum recorded impact force was approximately 7500 N, indicating the high energy involved in these collisions. Impact durations ranged from 0.05 to 0.11 milliseconds, emphasizing the rapid nature of the interactions. The deformation patterns were consistent across all particles, supporting the applicability of Hertz’s contact theory.This study offers valuable insights into the dynamic impact characteristics of iron ore particles, which are essential for optimizing the design and performance of mining machinery.

Study on the Dynamic Fracture Properties of Defective Basalt Fiber Concrete Materials Under a Freeze-Thaw Environment.

This study examines the crack resistance of basalt-fiber-reinforced concrete (BFRC) materials subjected to freeze-thaw cycles (FTCs). We utilized a φ50 mm Split Hopkinson Pressure Bar (SHPB) apparatus alongside numerical simulations to carry out impact compression tests at a velocity of 5 m/s on BFRC specimens that experienced 0, 10, 20, and 30 FTCs. Additionally, we investigated the effects of basalt fiber (BF) orientation position and length on stress intensity factors. The results reveal that with an increasing number of FTCs, the dynamic crack propagation speed of BFRC with a prefabricated crack inclined at 0° rises from 311.84 m/s to 449.92 m/s, while its pure I fracture toughness decreases from 0.6266 MPa·m0.5 to 0.4902 MPa·m0.5. For BFRC specimens with a prefabricated crack inclination of 15°, the dynamic crack propagation speed increases from 305.81 m/s to 490.02 m/s, accompanied by a reduction in mode I fracture toughness from 0.3901 MPa·m0.5 to 0.2867 MPa·m0.5 and mode II fracture toughness from 0.6266 MPa·m0.5 to 0.4902 MPa·m0.5. In the case of a prefabricated crack inclination of 28.89°, the dynamic crack propagation speed rises from 436.10 m/s to 494.28 m/s, while its pure mode II fracture toughness decreases from 1.1427 MPa·m0.5 to 0.7797 MPa·m0.5. Numerical simulations indicate that fibers positioned ahead of the crack tip-especially those that are longer, located closer to the crack tip, and oriented more perpendicularly-significantly reduce the mode I stress intensity factor. However, these fibers have a minimal impact on reducing the mode II stress intensity factor. The study qualitatively and quantitatively analyzes the crack resistance of basalt-fiber-reinforced concrete in relation to freeze-thaw cycles and the fibers ahead of the crack tip, offering insights into the fiber reinforcement effects within the concrete matrix.

A study on the effect of crack orientations, crack types and SHPB characteristics on the failure behaviour of pre-cracked sandstone rock specimens

The present study aims to understand the experimental and numerical behavior of intact and pre-cracked fine-grained sandstone specimens under indirect dynamic tensile loading conditions. The dynamic experimental analyses are carried out using the split Hopkinson pressure bar (SHPB) device to determine the tensile strength of sandstone rock. In addition to the dynamic tests, the physical, petrological, and mechanical tests under static loading of the sandstone rock are also studied. Thereafter, a three-dimensional (3D) finite element (FE) numerical model is developed, and a strain rate-dependent modified Drucker Prager constitutive model is used to validate the numerical model with the indirect dynamic tensile experimental test results. The validated parameters are then used to determine the behavior of pre-cracked sandstone specimens through numerical simulations. Two sets of numerical models with diametral cracks and cross-sectional cracks are introduced into the intact rock specimens. The orientation of the crack is changed from 0° to 90° and the numerical analyses are performed for 0°, 30°, 45°, 60°, 75° and 90° crack orientations with respect to the loading axis of the bars in the SHPB setup. Along with crack orientations, the loading rate is changed with varying gas gun pressures for the two sets of numerical models. The stress-strain responses are retrieved from the center and tip of the pre-crack introduced in the sandstone specimen. A comparative analysis is conducted for the responses obtained at the center and tip of the diametral and cross-sectional cracks and the results are stated herein.

Enhancing puncture resistance in critical applications: A combined experimental and numerical approach

The qualification of materials for puncture resistance is essential for applications like pressure vessels and transport containers, particularly for the safe transport of radioactive materials. International regulations, set forth by organizations such as the International Atomic Energy Agency (IAEA) and the Atomic Energy Regulatory Commission (AERB), mandate the design of transport packages capable of withstanding various accident scenarios, including puncture, fire, impact, and immersion, to ensure the safety and integrity of radioactive material transport. This paper establishes a correlation between puncture energy ( E) required to penetrate stainless steel and mild steel plates, both with and without lead backing, as a function of plate thickness ( t) and punch diameter ( d). The simulation of strain and damage caused by punch impact is carried out within the elastoplastic region of structural materials, with a focus on the kinetic strengthening of the material. Abaqus finite element software is employed for numerical simulations, with model parameters derived from experimental stress-strain flow curve data using a curve-fitting technique. Dynamic compression experiments were conducted at the Refueling Technology Division (RTD) in the Bhabha Atomic Research Center (BARC) across a range of strain rates from 600 [Formula: see text] to 1750 [Formula: see text] at room temperature, using a Split Hopkinson Pressure bar. Additionally, drop weight tower (DWT) experiments were performed at RTD in the BARC facility to calibrate numerical simulations. These experiments were carried out on both bare and leaded stainless steel (SS304L) and mild steel (SA516Gr70) plates.

Experimental Study on the Changes to the Microstructures and Dynamic Mechanical Properties of Layered Sandstone After High-Temperature Treatment

In this study, changes in the basic physical properties, mineral composition, mass, and microstructure of layered sandstone were evaluated following heat treatment at 200–800 °C. Dynamic impact compression tests were performed using a split-Hopkinson pressure bar test system (SHPB), and digital image correlation (DIC) was used to monitor the dynamic failure processes of the involved specimens. Results indicate that high-temperature treatment reduces the mass, wave velocity and peak stress of layered sandstone; increases the porosity, pore length, and pore aperture. The rates of decrease in the wave velocity and peak stress considerably increase with increasing temperature above a threshold of 400 °C. This is because at temperatures above 400 °C, thermal cracks will form both between and within particles. As the number of cracks increases, they will propagate and connect with each other, forming a network of cracks. DIC results show that as the heat treatment temperature rises, the range of the strain-concentration areas, which are formed by sandstone failures, substantially expands. However, the increase in the heat treatment temperature only negligibly influences the propagation direction of primary sandstone cracks, which mainly propagate along the weak bedding planes.

THE INFLUENCE OF THE STRAIN RATE ON THE VALUE OF FRICTION COEFFICIENT

The Male and Cockroft ring compression test stands as one of the methods utilized to determine the coefficient of friction in forming processes. This approach eliminates the need for force measurement. This study presents the outcomes of the Male and Cockroft ring compression test conducted on Hardox 450 material at varying strain rates, conducted without lubricant. The experiments were carried out using a ZD 40 hydraulic press, CFA-80 pneumatic die hammer and split Hopkinson pressure bar test at the Faculty of Mechanical Engineering of Brno University of Technology. The test results were documented on a calibration diagram, revealing a significant influence of strain rate on the coefficient of friction. Specifically, the findings indicate that as the strain rate increases, the coefficient of friction decreases.