Fatigue Strength Research Articles

Fatigue and Ultimate Strength Evaluation of GFRP-Reinforced, Laterally-Restrained, Full-Depth Precast Deck Panels with Developed UHPFRC-Filled Transverse Closure Strips

A depth precast deck panel (FDDP) is one element of the prefabricated bridge element and systems (PBES) that allows for quick un-shored assembly of the bridge deck on-site as part of the accelerated bridge construction (ABC) technology. This paper investigates the structural response of full-depth precast deck panels (FDDPs) constructed with new construction materials and connection details. FDDP is cast with normal strength concrete (NSC) and reinforced with high modulus (HM) glass fiber reinforced polymer (GFRP) ribbed bars. The panel-to-girder V-shape connections use the shear pockets to accommodate the clustering of the shear connectors. A novel transverse connection between panels has been developed, featuring three distinct female-to-female joint configurations, each with 175-mm projected GFRP bars extending from the FDDP into the closure strip, complemented by a female vertical shear key and filled with cementitious materials. The ultra-high performance fiber reinforced concrete (UHPFRC) was selectively used to joint-fill the 200-mm transverse joint between adjacent precast panels and the shear pockets connecting the panels to the supporting girders to ensure full shear interaction. Two actual-size FDDP specimens for each type of the three developed joints were erected to perform fatigue tests under the footprint of the Canadian Highway Bridge Design Code (CHBDC) truck wheel loading. The FDDP had a 200-mm thickness, 2500-mm width, and 2400-mm length in traffic direction; the rest was over braced steel twin girders. Two types of fatigue test were performed: incremental variable amplitude fatigue (VAF) loading and constant amplitude fatigue (CAF) loading, followed by monotonically loading the slab ultimate-to-collapse. It was observed that fatigue test results showed that the ultimate capacity of the slab under VAF loading or after 4 million cycles of CAF exceeded the factored design wheel load specified in the CHBDC. Also, the punching shear failure mode was dominant in all the tested FDDP specimens.

INDICATOR PHYSICAL FITNESS USING NORMAL AND OVERWEIGHT BODY MASS INDEX MEASUREMENT METHOD IN STUDENTS

Background. Everyone should place a high premium on physical fitness because a fit body allows one to perform everyday chores and responsibilities at their best. Body mass index, which measures dietary status, is one element that affects physical fitness. (BMI). This study intends to assess the physical health and BMI of students at the Adventist University of Indonesia's Faculty of Nursing. With Spearman's rho test, this study technique is quantitative. There were 70 participants who voluntarily and consciously gave their consent. The Zuchora Physical Fitness Test, height measuring equipment, and weight scales were the research tools employed. Results: A significant negative connection between BMI and physical fitness, speed, and arm strength was found using the Spearman Rho test (p.05). Jumping ability, flexibility, endurance, and muscle strength did not have a significant association with BMI (p > 0.05), however. The findings of this study suggest that BMI has an impact on physical fitness in terms of arm speed and strength. The speed and arm strength decrease as BMI increases.

Influence of Continuous Rotation and Optimal Torque Reverse Kinematics on the Cyclic Fatigue Strength of Endodontic NiTi Clockwise Cutting Rotary Instruments.

Objectives: The objective of the present study was to evaluate the cyclic fatigue strength of clockwise cutting rotary endodontic instruments when subjected to two different kinematics: continuous clockwise rotation and clockwise reciprocation movement under optimum torque reverse (OTR) motion. Methods: New ProTaper Next X1 (n = 20) and X2 (n = 20) instruments were randomly divided into two subgroups (n = 10) based on kinematics (continuous rotation or OTR). The specimens were tested using a custom-made device with a non-tapered stainless-steel artificial canal measuring 19 mm in length, featuring a 6 mm radius and an 86-degree curvature. All instruments were tested with a lubricant at room temperature until a fracture occurred. The time to fracture and the length of the separated fragment were recorded. Subsequently, the fractured instruments were inspected under a scanning electron microscope for signs of cyclic fatigue failure, plastic deformation, and/or crack propagation. The subgroup comparisons for time to fracture and instrument length were performed using the independent samples t-test, with the level of statistical significance set at 0.05. Results: When using OTR movement, the ProTaper Next X1 increased the time to fracture from 52.9 to 125.8 s (p < 0.001), while the ProTaper Next X2 increased from 45.4 to 66.0 s (p < 0.001). No subgroup exhibited plastic deformations, but both showed dimpling marks indicative of cyclic fatigue as the primary mode of failure. Additionally, OTR movement resulted in more metal alloy microcracks. Conclusions: The use of OTR motion extended the lifespan of the tested instruments and resulted in a higher number of metal microcracks. This suggests that OTR motion helped to distribute the mechanical stress more evenly across the instrument, thereby relieving localized tension. As a result, it delayed the formation of a single catastrophic crack, enhancing the overall performance of the instruments during the experimental procedures.

RESISTANCE OF HEAT-RESISTANT YTTRIUM-CONTAINING SEALING COATINGS TO MECHANICAL FRACTURE WHEN FORMING CUTTING PATHS

According to the results of tribotechnical tests of coatings made of KNA-82 alloy ligatures with the addition of yttrium of 0.1%, 0.3%, 0.5%, data were obtained that allowed us to establish the nature of changes in the dynamic coefficient of friction over the test period and numerous values of the energy intensity of material wear. The evaluation of coatings formed by the gas-flame and ion-plasma method was based on the following premise. The maximum resistance to mechanical fracture is determined by the manifestation of a constant minimum value of the dynamic coefficient of friction. This serves as an indicator of reduced friction force before reaching the fatigue limit. Another key factor is the number of separated particles produced per unit of integral work during the friction process. These evaluation parameters are lined up in a row by the number of points from 1 to 4. The maximum score corresponds to the maximum resistance, i.e., a lower value of the energy intensity of material wear and the minimum value of the stable friction coefficient. It has been determined that the same coincidence of these parameters according to the scores is almost at all stages of testing (I-III) was the coating formed by the gas-flame method with a yttrium concentration of 0.3%-0.5%. The exception was the coating formed by the ion-plasma method with a yttrium concentration of 0.1% at the fourth stage of testing.

Assessment of the Impact of Bone Quality and Abutment Configuration on the Fatigue Performance of Dental Implant Systems Using Finite Element Analysis (FEA).

The aim of this study was to evaluate the influence of abutment angulation, types, and bone quality on fatigue performance in dental implant systems. Three-dimensional models of maxillary 3-unit fixed implant-supported prostheses were analyzed. Abutments with different angles and types were used. Healthy bone (Hb) and resorbed bone (Rb) were used. Conducted on implants, a force of 150 N was applied obliquely, directed from the palatal to the buccal aspect, at a specific angle of 30 degrees. The stress distribution and fatigue performance were then evaluated considering the types of bone used and the angles of the three different abutments. The simulation aspect of the research was carried out utilizing Abaqus 2020 software. In all models, fatigue strengths in healthy bone were higher than in resorbed bone. Maximum stress levels were seen in models with angled implants. In almost all models with resorbed bone, fatigue performances were slightly lower. Increasing the abutment angle has been shown to increase stress levels and decrease fatigue performance in the adjacent bone and along the implant-abutment interface. In general, implants applied to healthy bone were found to have a higher success rate. It has also been suggested that multiunit abutments have beneficial effects on stress distribution and fatigue performance compared to resin cemented abutments. The type or angle of abutment and the quality of the bone can lead to biomechanical changes that affect the force distribution within the bone structure surrounding the implant. Clinicians can influence the biomechanical environment of the implant site by varying the abutment angle and type to suit the condition of bone health, potentially affecting the long-term success of implant treatment.

Rapid carburizing of low-alloy steel by atmospheric-controlled induction-heating fine-particle peening and investigation of its fatigue properties

Atmospheric-controlled induction-heating fine-particle peening (AIH-FPP) was applied to low-alloy, low-carbon steel AISI 4120 to achieve rapid carburizing within minutes and enhance fatigue strength. The shot particles used during AIH-FPP were specifically created by mechanically milling a mixture of steel particles and carbon powders. The specimens were analyzed using laser microscopy, optical microscopy, X-ray diffraction for residual stress measurement, a micro-Vickers hardness tester, and an electron probe micro-analyzer. Axial fatigue tests and fracture surface analyses via scanning electron microscopy and energy-dispersive X-ray spectroscopy were also conducted. AIH-FPP effectively transferred carbon to the treated surface and facilitated its diffusion in a short period, creating a martensite layer with high hardness and compressive residual stress, which resulted in increased fatigue strength. The fatigue strength of the AIH-FPP-treated specimens was influenced by the conditions of reheating and quenching, which altered the prior austenitic grain size and stress concentration at the specimen surface. Notably, specimens treated with AIH-FPP followed by reheating and water-injection quenching exhibited fatigue strength comparable to that of conventional gas-carburized specimens, owing to the formation of a carburized layer with a small prior austenite grain size.

Comparative Analysis of Mechanical Properties and Microstructure of 7B52 Aluminum Alloy Laser-MIG Hybrid Welding and MIG Welding Joints

Laser-MIG hybrid welding and MIG welding were carried out on 7B52 aluminum alloy, and the microstructure and mechanical properties of the joints were compared and analyzed. The results show that the average grain sizes of laser-MIG hybrid welding, MIG welding, and the laser weld zone are 18.38 μm, 24.16 μm, and 15.96 μm, respectively. The width of the HAZ of the laser zone is lower than that of the laser-MIG hybrid welding zone and MIG welding zone. The hardness is higher than that of the hybrid welding zone and MIG welding zone. The tensile strength of each laser-MIG hybrid welding joint zone is better than that of the MIG welding zone. The tensile strength of the laser zone is the worst. When stress ratio R = 0.1 and fatigue cycle Nf = 106, the fatigue strength of the laminated zone of the laser-MIG hybrid welding joint is better than that of the MIG welding joint, and the welding defect is the leading cause of fatigue cracks.

Effect of Coupling Ultrasonic Fatigue Strengthening and Polishing Methods on Open Hole Structures

Effect of Coupling Ultrasonic Fatigue Strengthening and Polishing Methods on Open Hole Structures

High cycle fatigue behavior and strengthening mechanisms of laser powder bed fusion pure tantalum

The fatigue behavior and strengthening mechanisms of the laser powder bed fusion pure tantalum (LPBF-Ta), coupled with a fatigue life prediction model, were originally explored. The fatigue strength of LPBF-Ta fabricated at the optimal laser energy density (154.16 J/mm3) is 348 MPa (106 cycles), showing a remarkable improvement of about 80 % and 50 % compared with that of the annealed and cold worked commercially pure tantalum, respectively. The microstructural analysis identifies that cellular structures averaging 300 nm in size contribute 438.2 MPa to strengthening, serving as the main contributor to fatigue strength. The breaching of cell walls by dislocations, along with the activation of cross-slip, ensures plasticity and ultimately enhances fatigue strength. Besides, the analysis of the defects reveals that the internal lack of fusion pore can induce the secondary fatigue crack, resulting in a region of brittle crack propagation. Furthermore, a finite life prediction model is established by originally incorporating the size of the crack source defect, and it significantly improves the prediction accuracy of the fatigue life. These results provide guidance for the development of fatigue strengthening strategies for LPBF-Ta.

Fatigue research of metro car body based on operational loads

PurposeThe principle of infinite life design currently directs fatigue resistance strategies for metro car bodies. However, this principle might not fully account for the dynamic influence of operational loads and the inevitable presence of defects. This study aims to integrate methods of service life estimation and residual life assessment, which are based on operational loads, into the existing infinite life verification framework to further ensure the operational safety of subway trains.Design/methodology/approachOperational loads and fatigue loading spectra were determined through the field test. The material test was conducted to investigate characteristics of the fracture toughness and the crack growth rate. The fatigue strength of the metro car body was first verified using the finite element method and Moore–Kommers–Japer diagrams. The service life was then estimated by applying the Miner rule and high-cycle fatigue curves in a modified form of the Basquin equation. Finally, the residual life was assessed utilizing a fracture assessment diagram and a fitted curve of crack growth rate adhered to the Paris formula.FindingsNeither the maximum utilization factor nor the cumulative damage exceeds the threshold value of 1.0, the metro car body could meet the design life requirement of 30 years or 6.6 million km. However, three out of five fatigue key points were significantly influenced by the operational loads, which indicates that a single fatigue strength verification cannot achieve the infinite life design objective of the metro car body. For a projected design life of 30 years, the tolerance depth is 12.2 mm, which can underscore a relatively robust damage tolerance capability.Originality/valueThe influence of operational loads on fatigue life was presented by the discrepancy analysis between fatigue strength verification results and service life estimation results. The fracture properties of butt-welded joints were tested and used for the damage tolerance assessment. The damage tolerance life can be effectively related by a newly developed equation in this study. It can be a valuable tool to provide the theoretical guidance and technical support for the structural improvements and maintenance decisions of the metro car body.

Effect of Pt-Al coating on low-cycle fatigue behavior in a Ni-based single crystal superalloy at 760 °C

The effect of Pt-Al coating on low-cycle fatigue behavior of Ni-based single crystal superalloy at 760 °C was evaluated. The results show that Pt-Al coating does not change the cyclic stress response behavior of the Ni-based single crystal superalloy at 760 °C. Under the total strain amplitude from 0.6 % to 1.2 %, the cyclic stress amplitude value of Pt-Al coating samples is slightly lower than uncoated samples during cyclic deformation at the stable stage under the same applied total strain amplitude, and the fatigue life of Pt-Al coating samples is lower than uncoated ones, with an average fatigue life reduction of about 19.9 %. By the relation curve of comparing the cyclic strain amplitude with the reversals to failure, it is observed that the fatigue ductility coefficient ε′f of the Pt-Al coating sample is higher than the uncoated sample, the fatigue ductility index c and fatigue strength coefficient σ′f are lower than the uncoated sample, but the fatigue strength index b has little difference. It is found that the cyclic strength coefficient K′ and the cyclic strain hardening index n' of the Pt-Al coating sample are lower than the uncoated sample after fitting the curves of the relationship between cyclic stress amplitude and total strain amplitude. In addition, the cyclic stress amplitude of Pt-Al coating sample is slightly lower than uncoated sample under the same applied total strain amplitude. It was found by SEM that the cracks of both uncoated and Pt-Al coating samples initialized near the surface of the samples under low-cycle fatigue loading at 760 °C, and multiple crack sources began to spread into the substrate. It was found by TEM observation that at low strain amplitude (Δεt/2 = 0.6 %), the dislocations in both uncoated and Pt-Al coating samples mainly converged in γ, and a large number of dislocation debris gathered in the γ and dislocation entanglement was generated, while a small number of dislocations were observed to cut into γ'. The γ′ is seriously deformed and slightly rafted at Δεt/2 = 1.2 %, and a few dislocations are also observed in γ'.

Static and cyclic behavior of high-performance concrete reinforced with hybrid steel fibers using notched and un-notched flexural specimen

In this paper, the static and cyclic behavior of high-performance concrete reinforced with hybrid steel fibers (HPFRCs) using notched and un-notched flexural specimen were experimentally studied. The term 'hybrid steel fibers' refers to using a combination of different steel fiber s in HPFRC mortar. Three HPFRC types, produced from an identical mortar, contained a same total fiber content of 2.0 vol% but different hybrid fiber systems as follows: 0.5, 1.0, 1.5 vol% long hooked fiber blended with 1.5, 1.0, 0.5 vol% short smooth, respectively. All flexural specimens were designed with a prism-shape having dimensions of 40 × 40 × 160 mm (width × depth × full length). Two specimen types were employed: un-notched and notched specimen with its depth of 5 mm at specimen bottom. The specimens were experimented under static and cyclic loading using a three-point bending test. Despite the lower peak static load, the notched specimen produced the higher flexural strength and critical stress intensity factor, regardless of the HPFRC types. Under cyclic loading, the number of cycles of the notched specimens showed lower than that of the un-notched specimens, for all the HPFRC types at same fatigue stress ratio. Besides, the higher static flexural strength seemed to produce the lower fatigue endurance limit, based on the proposed fatigue response curves built by regression technique.

A tail probability density distribution model of stress amplitude under band-limited stochastic vibration loadings

Resonance of engineering structures under stochastic vibration loadings is a primary cause of fatigue failure. Considering that cyclic loadings below the fatigue limit of the material contribute little to fatigue damage, the portion of the stress amplitude distribution that exceeds the fatigue limit is in focus in this paper, and a tail probability density distribution model of stress amplitude under band-limited stochastic vibration loadings is proposed. First, the response stress power spectral density functions under band-limited loadings are simulated by using the normal distribution and the Weibull distribution, respectively, and then the frequency domain signals are converted into time domain signals by adopting the inverse fast Fourier transform method. A two-parameter Weibull model of tail probability density distribution of stress amplitude is proposed, and the relationship between model parameters and power spectral moment parameters is given. Finally, the comparative analysis of the model accuracy and the vibration fatigue test of aluminum alloy notch specimen are carried out. It is demonstrated that the fatigue life predicted by the presented model is highly coincident with the results of tests and the time domain method.

Introducing deep trap states for high dielectric strength of aramid‐based composite films

AbstractAramid nanofiber (ANF)‐based composites have drawn tremendous interest in high‐voltage electrical systems due to their superior insulation strength, thermal stability, and mechanical endurance. However, the filler agglomeration and interface compatibility have retarded further improvement of the dielectric performance. Herein, the nano‐titanium dioxide (TiO2) particles treated by aminopropyl triethoxysilane (APTES) serve as the inorganic fillers, which are doped in the ANF to prepare the composite nano‐paper via the blade coating method. The electrostatic interaction between the ANF and fillers highly promotes their uniform distribution. Compared to the pure ANF paper, the composite paper has a denser structure with reduced pores and defects, which significantly improves its dielectric performance with inhibited partial discharge development. At a filler loading of 3 wt% (mass fraction), the breakdown strength is increased by 70.5% to a maximum value of 358.1 kV/mm, while the bulk conductivity is minimised to 5.2 × 10−17 S/m, representing an 88.1% decrease. By analysing the energy band structure of each component, energy barriers at the interface for electrons (1.48 eV) and holes (0.40 eV) are determined. These values indicate deepened trap energy levels, which greatly strengthen the carrier trapping effect for improved dielectric performance.

Multiscale modelling strategy for predicting fatigue performance of welded joints

This study predicts the fatigue performance of welded joints through a multiscale modelling strategy accounting for material and structural inhomogeneities. An S-N curve and detailed fracture surfaces with distinct beach marks were first derived by uniaxial fatigue tests utilising the designed cruciform welded joints. Considering the intrinsic features of welded joints, a multiscale modelling strategy was proposed to integrate multiple factors, including microstructural variations, strength distributions within the heat-affected zone (HAZ), and the diversity of three-dimensional weld toe shapes. Significantly, a modelling strategy was presented for the first time to simulate the simultaneous initiation, growth, and coalescence of multiple cracks, and was validated against experimental evidence. The results indicate that the proposed strategy can accurately predict both the fatigue strength and the overall crack growth process. Additionally, comparative assessments of single-crack and multiple-crack modelling strategies revealed notably shorter predicted fatigue lives when considering crack coalescence. Overall, this work establishes a multiscale framework for assessing the fatigue performance of welded joints considering both microscopic and macroscopic factors, offering substantial practical implications for engineering applications.

Experimental substantiation of the methodology for the development of physical qualities women of mature age (45-55 years)

This article deals with issues aimed at the development of middle-aged women who are able to stimulate the endurance of the abdominal press, the flexibility of the hamstrings, and the muscular endurance of the upper body after 12 weeks of physical exercises for two sessions of 60 minutes per week. Squats and push-ups increase strength and muscular endurance. A woman's physical condition is also largely tied to the phases of the menstrual cycle. At the same time, the manifestation of changes in the body of women during this period is very diverse. Menstrual health is a state of complete physical, mental and social well-being, and not just the absence of diseases or ailments associated with the menstrual cycle. This is the process of preparing the body for pregnancy. Menstrual health has a huge impact on society, from the impact on careers and opportunities to health issues. Menstruation greatly affects the physical performance of athletes due to symptoms such as cramps, back pain, headache and bloating. In addition, statistics claim that 75% of women who engage in any type of physical activity experience negative side effects due to their menstrual cycle. During menstruation, women suffer from several physical, psychological, and behavioral symptoms that often result from premenstrual syndrome (PMS). Approximately 75% of women suffer from PMS and may experience headaches, abdominal cramps, bloating, fatigue, anxiety, high stress levels, or a combination of these symptoms. These symptoms range from mild to so severe that some women take days off work. While this is difficult for women to deal with in general, it affects athletes even more, who often have to go through rigorous training and physical exertion on a daily basis.

Does Cathodal Preconditioning Enhance the Effects of Subsequent Anodal Transcranial Direct Current Stimulation on Corticospinal Excitability and Grip Strength?

Lewis, A, Rattray, B, and Flood, A. Does cathodal preconditioning enhance the effects of subsequent anodal transcranial direct current stimulation on corticospinal excitability and grip strength? J Strength Cond Res XX(X): 000-000, 2024-Inconsistent effects of transcranial direct current stimulation (tDCS) on corticospinal excitability (CSE) and exercise performance are commonly reported. Cathodal preconditioning, involving cathodal tDCS delivered before anodal tDCS over the same region, may enhance changes in CSE and exercise beyond that resulting from anodal tDCS alone. This study aimed to investigate whether the effects of anodal tDCS on CSE and isometric grip strength can be enhanced by cathodal preconditioning. Thirty-five healthy subjects aged 19-37 years completed a familiarization session followed by 4 stimulation conditions presented in a randomized cross-over design across 4 separate sessions. tDCS doses were applied at 2 mA over the primary motor cortex for 10 minutes. Corticospinal excitability was assessed using 120% of resting motor threshold and an input/output curve of motor evoked potentials of the first dorsal interosseous. Grip strength was evaluated as time to exhaustion (TTE) in a sustained isometric contraction. Relative to conventional sham stimulation, TTE was significantly increased by 15% after conventional anodal tDCS. Corticospinal excitability increased in response to tDCS, but this effect did not differ across conditions. Cathodal preconditioning before anodal stimulation did not increase CSE or grip strength beyond that seen in the other stimulation conditions. Our findings did not reveal any significant impact of stimulation type on CSE. Notably, anodal tDCS led to a significant improvement in grip strength endurance. However, cathodal preconditioning did not seem to increase the effect of subsequent anodal stimulation on CSE nor grip strength.

Recreational running as a means of training for the development of strength endurance for children and adolescents

Recreational running as a means of training for the development of strength endurance for children and adolescents

Crack failure behaviors of Ti–6Al–4V dovetail joints subjected to fretting fatigue and effect of laser shock dimple-textured surface coated with diamond-like carbon film

Fretting damage can lead to a reduction in fatigue strength by more than half, due to the increased stress on the fretting surface, which accelerates crack initiation and propagation. Laser shock peening (LSP) technology is an advanced method for protecting against fretting fatigue, which reduces the effective stress on the fretting surface of components by introducing a deeper compressive residual stress field. In this work, LSP was utilized to create regularly arranged dimples on the surface of titanium alloy dovetail joints, and followed by diamond-like carbon (DLC) coating to alter fretting friction. Five surface treatment samples including as-machined, conv-LSP, LSP dimple-textured, DLC, LSP dimple-textured + DLC, were prepared for fretting fatigue tests on dovetail joints. The experimental results showed that the fatigue performance of specimens treated with LSP dimple-textured + DLC is better. Furthermore, it is found that wear debris from fretting surface was discharged into crack source area during fretting fatigue, leading to the formation of a fracture debris area forms in the crack initiation zone. The crack initiation zone displays the protrusion morphology characteristics due to the friction effect induced by contact loads. There is an internal correlation between the size of fracture debris area and surface wear resistance. Fracture debris area and the protrusion morphology vary with surface treatments and applied load. This research further reveals that the variation characteristics of the crack initiation area including the fracture debris area, have a positive influence on observing and analyzing failure behavior of fretting fatigue damage.

Специфика физической подготовки студентов-мужчин к сдаче норматива ГТО в разделе «рывок гири» в образовательных организациях высшего образования

Physical fitness is an important component of the lives of students, especially men, and plays a key role in achieving academic success and beyond. Within the framework of higher educational institutions, special attention is paid to passing the Ready for Labor and Defense Standards, one of the main sections of which is the “kettlebell jerk”, which requires students to show strength, coordination and endurance. The analysis of the results of the conducted research on the preparation for the delivery of the Ready for Labor and Defense Standards complex “kettlebell jerk” is also presented. Male students of Vyatka State University took part in the study. They were divided into 2 groups: experimental and control. Both groups passed the Ready for Labor and Defense Standards “kettlebell jerk” complex, and then, for two months, the control group trained according to the rules of kettlebell lifting, and the experimental group trained the kettlebell jerk according to the rules of the army jerk. After that, the groups re-passed the same standard. The results obtained before and after the experiment were compared. In the course of the study, it was revealed that the kettlebell lifting specialists of the experimental group, who received a training complex based on the rules of the army kettlebell jerk, showed had higher indicators of hand strength and overall functional endurance in the competitive movement of the 16 kg kettlebell jerk compared with the group that performed exercises according to the rules of kettlebell lifting with one interception of the kettlebell when performing a jerk.