We discuss experimental and numerical studies of the deformation and destruction of fine-grained concrete B22.5 under dynamic loading. The experiments were carried out using the Kolsky (or split-Hopkinson pressure bar) method, and its modifications in the strain rate range from 400 to 2000 s(-1). The rate dependences of ultimate stresses and fracture energy in tension and compression are obtained. Based on experimental data, the identification of the dynamic component of two models from the LS-DYNA computational complex was carried out: *MAT_CONCRETE_DAMAGE and *MAT_CSCM. The results of a comparative analysis of the identified models based on single-element modeling and comparison with experimental data are presented. It is shown that the obtained experimental strain rate dependences of the fracture characteristics can significantly improve the predictive ability of the model compared to the default parameter set. Information about the rate dependence of the fracture energy in *MAT_CSCM model makes it possible to more realistically simulate the behavior of the material beyond the ultimate stress.

An experimental study of the dynamic properties of fine-grained concrete reinforced with fine-meshed meshes under dynamic uniaxial compression relative to the original fine-grained concrete has been carried out. Reinforced samples were made by pouring concrete into molds with pre-installed mesh frames. Dynamic tests have been carried out. Dynamic compression tests were carried out using the Kolsky method at strain rates from 30 to 600 s−1. The paper presents the composition of the test material, test parameters, as well as a comparative analysis of the data obtained. The introduction of reinforcing meshes into the original fine-grained concrete increased the dynamic strength of the material. The dependences obtained demonstrate that the maximum breaking stresses achieved in the experiments increase linearly with the growth of the strain rate, as do the corresponding limiting strains. The time before the onset of fracture decreases with increasing strain rate according to a power law.

An experimental study of the dynamic properties of three types of fiber-reinforced concrete under dynamic uniaxial compression relative to the original fine-grained concrete was carried out. Three types of fiber-reinforced concrete were produced: with polymer fiber, steel fiber, and with a combination of two types of fiber. Static and dynamic tests were carried out. Dynamic compression tests were carried out using the Kolsky method at strain rates from 102 to 103 s−1. The tests were carried out using a FASTCAM Mini UX100 high-speed camera. The paper presents the compositions of the studied materials, test parameters, as well as a comparative analysis of the data obtained. The introduction of a reinforcing fiber into the original fine-grained concrete increased the dynamic strength of the material. The highest strength under dynamic uniaxial compression was shown by fiber-reinforced concrete with steel fiber. The dependences obtained demonstrate that the maximum breaking stresses achieved in the experiments grow linearly with an increase in the strain rate, as do the corresponding limiting strains. The time before the onset of fracture decreases with increasing strain rate according to a power law.

This paper analyzes an experimental study of high-rate deformation and fracture of fine-grained concrete under tensile stresses. A number of sources of foreign and domestic authors are analyzed. Based on the analysis, it was concluded that some properties of concrete have not been fully investigated. In connection with the above, an experimental study of the dynamic properties of concrete materials is relevant today. Experimental studies were carried out on the basis of modifications of the Kolsky method. These modifications make it possible to determine the strength and time characteristics of concrete deformation under high-speed loading. To analyze the nature and time of the destruction, experiments were carried out using high-speed photography. Splitting (Brazilian test) and straight tensile experiments have two speed modes. On the basis of the performed experimental work, tensile strain diagrams and stress versus time diagrams during splitting were obtained. The experimental data indicate the effect of the strain rate on the ultimate tensile strength characteristics. The dynamic tensile strength of fine-grained concrete was about 8 MPa. The value of the coefficient of dynamic tensile hardening is in the range from 4 to 6 MPa. This factor depends on the strain rate. The opposite effect of the influence of the loading rate was obtained both during splitting and stretching. This means that with an increase in the strain rate, the maximum breaking stresses decrease. On the basis of high-speed photography, the features of high-speed destruction of fine-grained concrete under tensile stresses are revealed. The found characteristics can be used to create mathematical models necessary to determine the strength of concrete structures subjected to dynamic effects.

Investigation of the behaviour of structural materials in a wide range of the strain rates is an urgent task. The sources of dynamic loads originate from explosion, shock, and earthquake vibration. The loading rate is an important index corresponding to different velocities of impacts for construction materials. The strain rate of structures under impact loading is in the range of 0.1–200 s−1, but it is more than 200 s−1 under blast loading. The rock engineering often involves the dynamic loading scenarios, such as excavation engineering, civil engineering, blasting engineering, projectile impact, seismic events, and rock collapse. There is still limited data in strain rate regimes of relevance, specifically for drop shock applications. This paper describes a pneumo-dynamic experimental setup created in the dynamic testing laboratory of the Research Institute for Mechanics of Nizhny Novgorod State University, to study the dynamic behaviour of structural materials at strain rates of the order of 100 s−1. The results of approbation are given on the example of dynamic tests of plate specimens made of steel HX220BD.

The paper presents the results of dynamic tests of some titanium alloys. The tests for compression, tension, and shear were caпied out using the Kolsky method and its modifications. In addition, a technique for determining the dynamic coefficient of friction, based on the Kolsky method, was implemented. As a result of the tests, dynamic, and static strain diagrams were plotted. Ultimate strength dependencies versus strain rate (yield stress σ02, ultimate tensile strength σB, ultimate plasticity characteristics, axial strain δ and lateral strain ψ at fracture) were determined on the basis of the diagrams. The positive sensitivity of the strength characteristics to the strain rate was noted for the tested materials. At the strain rates more than 5 × 102 s−1 the intensive growth of the strength characteristics is observed. The ultimate plasticity characteristics weakly depend on the strain rate. For the titanium alloy, the value of the dynamic coefficient of friction was obtained, which turned out to be close to its static value. The parameters of the well-known Johnson-Cook model were calculated using the obtained data. Verification experiments were performed, the results of which were compared with the results of virtual (computational) experiments. Good qualitative and quantitative agreement between experimental and numerical results was noted.

The paper considers distinguishing features of the experiment on visco-plastic materials subjected to high strain rate tension, namely non-uniformity of stress–strain state in the working part of a specimen due to the existence of fixing parts and plastic strain localization. The modification of the Kolsky method (or Split Hopkinson Pressure Bar method) is used as experimental technique. The main experimental setup configurations for testing specimens under high strain rate tension are reviewed. We present mathematical models used for assessment of stress components distributed in a neck. The numerical modeling of high rate tension of a visco-plastic axisymmetric specimen is performed, allowing the accuracy of above models to be estimated. The experimental–numerical procedure used to construct a true stress–strain curve on the basis of high rate tensile experiment is described.

This work describes system of basic experiments for dynamic testing of fibro-concrete based on the Kolsky method. Those experiments allow to determine a set of strength characteristics of fibro-concrete under high-rate loading. Some examples are given.

Tests on birch and aspen with different directions of cutting samples relative to the location of the fibers were performed. The tests were carried out on the installation with a Split Hopkinson Pressure Bar (SHPB) that implements the Kolsky method. The angles between the direction of application of the load and the direction of the location of the fiberswere 0°, 30°, 45°, 60° and 90°. The experiments were carried out at temperatures of −40 °C, +20 °C and +60 °C. The strain rate was of the order of 103 s−1. Dynamic stress-strain diagrams were obtained. The greatest steepness of the load branches and the greatest destructive stresses were observed for samples with a cutting angle of 0°. The smallest values of these parameters are noted at 90° cutting angle. It is noted that as the temperature of the test decreases, the magnitude of the stresses at which the specimens are destroyed increases for all the cutting angles of the specimens. There is a tendency to a decrease in the diagrams at a temperature of +60 °C compared with the results at room temperature for almost all tested wood batches. At the same time, both the modules of the loading and unloading branches and the limiting (destructive) stresses decrease.