Dynamic Overloads Research Articles

Computational Models of Dynamic Load Sources for Modeling of Construction Structures Operation Used in Monitoring of Technical Condition of Buildings and Structures

This research aims to develop principles for assessing the impact of mega-cyclic vibrodynamic loads on the reliability of construction structures. The relevance of the reasons for the development and improvement of algorithms for numerical modeling of multicycle dynamic loads on building structures is due to the steadily increasing intensity of such loads on buildings and structures in megacities, as well as the acute practical problem of significant differences in the dynamic characteristics of buildings and structures obtained as a result of mathematical modeling and determined by experimental methods. The article presents research materials on computational equivalent models of dynamic load sources for numerical modeling of the behavior of construction structures under their influence, using the method of vibroacoustic analogies. The article examines models of sources of dynamic impact on construction sites. Algorithms and final formulas for computational modeling of the simplest sources of dynamic load are developed using the method of vibroacoustic analogies. The dynamic properties of the simplest dynamic load sources were analyzed. A significant difference between the computational models of real and ideal dynamic load sources. The article presents research and development results intended for calculating the distribution of dynamic loads on elements of construction structures in industrial and civil engineering projects located in areas with high levels of transport vibrodynamic impacts. An important property of the proposed computational equivalent models of sources of dynamic impact on building structures is the possibility of computational verification of critical elements, points, or nodes of load-bearing structures of buildings and structures under dynamic overloads. The position of these critical elements, points, and nodes of load-bearing structures under dynamic loads can differ significantly from their position determined using static and quasistatic computational modeling methods.

Режими роботи маніпулятора ремонтно-евакуаційної машини

With modern methods of conducting military operations, the system of technical support of the troops is of great importance. One of the ways to increase the effectiveness of the system of technical support of troops is the use of armored repair and evacuation vehicles. It is possible to increase the technical capabilities of armored repair and evacuation vehicles by modernizing existing models, or creating qualitatively new vehicles that take into account the specifics of use and characteristic combat damage of modern weapons and military equipment, the type of engine of the military vehicle, its weight and dimensions and other characteristics. Improvement and modernization of armored repair and evacuation vehicles allows to ensure their effectiveness. Armored repair and evacuation vehicles demonstrate high efficiency when carrying out operations to extract or lift damaged or stuck, blocked, bogged down, sunken military equipment. In these cases, the traction force of the armored recovery vehicle's own engine is used or its own specialized means of evacuation: crane winches, polyspatch systems, crane booms together with power hydraulic cylinders of their drive, levers, other evacuation equipment. Features of the lifting and loading equipment include such modes of operation as lifting loads from a solid surface, detaching the load from a viscous surface, dragging at different angles to the support surface, and getting stuck. The most difficult in terms of dynamic overloads of all elements of the hydraulic manipulator is the mode of partial immersion and dense sticking of the load in clay soil, when after separation from it, the load under the action of the forces of elastic deformations of the suspension flies up to the height of a significant relaxation of the suspension and reaching the upper point, where its speed is zero, falls down on an elastic suspension. At the same time, a three-fold overload of the manipulator links is observed.

Artificial hypobiosis as a method of G-force negative impact reduction

Dynamic gravitational acceleration, known as a G-force, is an extreme factor for some professions. G-force negative impact realizes in central nervous system adequate functioning disturbance, resulting from oxygen starvation of tissues due to hemodynamic disorders. Known methods of G-force protection are aimed at increasing the maximum short-term G-force value, but not its total safe duration. In a number of studies, in order to increase the maximum value of the tolerated overload, we introduced laboratory animals into a state of artificial hypobiosis. The authors noted a decrease in mortality with an increase in the maximum value of the overload force. There were no data on manifestations of disorders of the central nervous system and recovery time, as well as changes in the safe duration of overload.
 The study aims to assess the change in the safe G-force duration while artificial hypobiosis.
 Scientists have used Syrian male hamsters weighing 95.5=0.5 g (M=m) in the study. We have divided the animals into groups — experimental and control.
 To induce artificial hypobiosis, the researchers administered intramuscular injections of a suspension of α-methyldopa to animals of the experimental group. The control group received of 0.9% NaCl. We have carried out dynamic gravitational acceleration modeling using a centrifuge (r=0.62 m). The animals of both groups were conscious, with positive G-forces pointing downward (head-pelvis).
 Within 10 seconds (s), the centrifuge rotation speed was increased till the chosen G-force value, G: 30 (angular velocity (ω)=21.79 rad/s), 40 (ω=25.16 rad/s) or 70 (ω=33.28 rad/s). G-force exposure set time, s: 20, 50, 80, 110 or 140. After a complete stop for 10 seconds, the general condition of the animals, injuries, hemorrhages, breathing, heart contractions were assessed. We monitored the surviving animals, assessed consciousness, determined coordination disorders in accordance with the following criteria: animal posture, productive movement, unstable gait, circular motion, reclining on the side. The time of restoration of coordination was also determined. The researchers have observed the animals during the following days to assess the daily survival rate. Necropsy was performed on all non-surviving animals.
 Survival in the control group: 30 G: 80 s — 5/6; 40 G: 20 s — 6/6, 50 s — 6/6, 80 s — 3/6; 70 G: 20 s — 6/6, 50 s — 4/6, 80 s — 0/10. Survival in the experimental group: 70 G: 50 s — 6/6, 80 s — 10/10, 110 s — 10/10, 140 s — 2/6.
 After acceleration of 70 G 50 s in animals of the experimental group, coordination disorders were weakly expressed, the coordination recovery time was 1.8±0.3 s, in animals of the control group, violations were assessed as significant, the recovery time was 4.5±0.3 s, which is 2.5 times (p<0.01) more.
 On the following day, tremor persisted in 3 animals of the control group 40 G 80 c. In the remaining animals of all groups, no coordination disorders or peculiarities were detected.
 We did not find any external injuries in any animal. Also, the scientists did not reveal a violation of the integrity of tissues according to the results of histological examination.
 The authors have proved a 5.5-fold increase in the time of safe stay of animals in a state of artificial hypobiosis during dynamic overloads. There was a 2.5-fold decrease in the coordination recovery time in animals in a state of artificial hypobiosis.
 Ethics. Studies involving laboratory animals were conducted in compliance with the necessary regulations (the Helsinki Declaration of 2000 on Humane Treatment of Animals and the "Rules for carrying out work using experimental animals" (Order of the Ministry of Health of the USSR No. 755 of 12.08.1977)). The Ethics Committee of Izmerov Research Institute of Occupational Health approved the protocol of the study.

Development of a piezoelectric-hydraulic series hybrid vibration exciter undergoing dynamic overloads

Development of a piezoelectric-hydraulic series hybrid vibration exciter undergoing dynamic overloads

Methods of Optimization of Mining Operations in a Deep Mine—Tracking the Dynamic Overloads Using IoT Sensor

Methods of Optimization of Mining Operations in a Deep Mine—Tracking the Dynamic Overloads Using IoT Sensor

Phenomenological hysteretic model for fixed-end steel equal-leg angle: Development and application

Hysteretic behaviors of steel members are of great significance in the assessment of the realistic ultimate capacity of steel structures subjected to dynamic overloads (e.g. strong earthquakes). To this end, this paper intends to develop a new phenomenological hysteretic model for capturing the inelastic behaviors of steel equal-leg angles, which is extensively used in a latticed steel tower. Specifically, cyclic tests of steel angles were performed, and a 3D finite element (FE) model is developed and validated based on the experimental results. Numerical parametric analyses are then performed to investigate the influences of slenderness ratios, width-to-thickness ratios, and initial imperfections on the hysteretic behaviors of steel equal-leg angles. Based on the parametric results, a phenomenological hysteretic model is proposed to replicate the hysteretic behaviors of steel angles, and its accuracy is demonstrated by further comparing against the experimental results. Finally, the proposed phenomenological hysteretic model is coded into the commercial package ABAQUS and used to simulate the dynamic responses and collapse of a latticed tower under severe earthquakes. The results show that the proposed phenomenological hysteretic model shows high fidelity in reproducing the nonlinear hysteretic behaviors of steel equal-leg angles subjected to cyclic loads. This research can enrich the existing hysteretic models of steel members and provide an accurate method for estimating the realistic responses of steel structures subjected to strong dynamic overloads.

Application of Spectral Entropy in Haul Truck Joint Damage Detection.

Early detection of machine failures is often beneficial, both financially and in terms of worker safety. The article presents the problem of frequently damaged joints in haul trucks, which are a real threat to the health and life of drivers. It was decided to investigate the problem in terms of dynamic overloads using two NGIMU inertial sensors and placing them in two places on the machine in close proximity to a joint. The data were captured during the standard operation of various machines in several mining departments, which allowed for the detection of a variety of factors influencing vibration. A hypothesis was developed that any changes in the joint would cause a change in the characteristics of vibrations, which were measured using the spectral entropy of vertical vibrations. Analyses have shown that there is a relationship between the change in spectral entropy difference (between the front and back of the vehicle) and joint events: nut tightening, nut replacement, and even joint fracture and replacement. The presented results offer the potential to create a tool for joint diagnostics and the early detection of damage or backlash.

Mechanical energy dissipation due to the propagation of elastic waves during the lateral impact of elastic cylinders

The lateral impact between elastic cylinders is studied using two dynamic models. We propose an elementary example to justify the mechanical energy dissipation in a pure elastic contact and to define the parameters needed for its quantification. A finite element model is presented as the theoretical basis for the quantification of the mechanical energy dissipation produced by the propagation of elastic waves in continuous deformable impacting cylinders. The results are exploited to build an accurate and more numerically efficient dynamic lumped parameter model. The models are applied to the lateral impact of identical cylinders with various diameters and different impact speeds. The impact of the cylinders with a different mass and radius is also analyzed. The calculation of the coefficient of dissipation enables the global loss of mechanical energy to be quantified, and an equivalent damping ratio associated with the impact is calculated. The obtained damping values can be used as a reasonable underestimate of the dissipation produced in the engagement of spur gears, thus allowing a conservative prediction of the dynamic overloads of the system in resonant conditions.

Theoretical consideration of fatigue strengthening of conical picks for rock cutting

Rock mining is a key process associated with the drilling of tunnels and underground mine roadways and the extraction of useful minerals in mines. Under suitable conditions (rock workability), it is performed through cutting using conical picks. This technique is used not only in tunneling or mining but also in civil engineering—for example, in the construction of underground architectural objects using trenchless, approaches, or in road construction—for example, to renovate asphalt and concrete road surfaces, squares, or runways at airports. Picks experience wear and tear during the cutting process, or even destruction, which can decrease mining efficiency. Thus, it is necessary to replace picks on the working units of mining machines. Body breakage is one of the most severe forms of pick damage. This effect can be ad hoc, or more often fatigue. Fatigue cracking occurs suddenly in the pick bodies, without any clear preceding signs to allow corrective actions to be taken. Such loss of picks significantly affects the mining process, resulting in dynamic overloads of the mining machine, increased vibrations accompanying its operation, high energy consumption during the mining process, and increased exposure to dust. Damage resulting from the loss of picks due to various causes, such as breakage, is usually costly to repair, as it necessitates the replacement of important elements of the cutting system (e.g. cutting heads), which leads to unplanned downtime and expenditure. This article addresses the issue of eliminating such undesirable defects of cutting picks. The mechanism underlying fatigue destruction of conical pick bodies during their operation is described. The paper also defines pick fatigue life and highlights the factors influencing this parameter. Furthermore, this work aimed to propose a new design and technological solution for the conical picks equipped with a compressed reinforcing sleeve. The design requirements for this type of picks were determined with the goal of ensuring efficient strengthening action of the reinforcing sleeve, which in turn can significantly increase the fatigue life of conical picks.

Determination of destruction cause of experimental mill roll of stand roughing group of mill 150.

High quality of purchased resources plays a critical role under the conditions of severe international competition. Raw materials, materials and components are purchase for product production and their quality is an essential part in the production of steel at OJSC “BSW – Management Company of the Holding “BMC” holding». The problem of excessively high level of dynamic loads is especially acute for roughing stands. The main reasons for dynamic overloads are intense transient processes occurring in the rolling cycle, the presence of elastic constraints and gaps in the system, imperfection of electric drive system and errors made during development. Therefore, there is a need for selection of material and manufacturing technology for mill rolls capable to withstand such loads for a sufficiently long period. Investigations of destruction causes of experimental mill roll of stand roughing group of mill 150 of section rolling shop at OJSC “BSW – Management Company of the Holding “BMC” holding were carried out. Main classification features are established based on the analysis of the fracture. The results of metallographic studies of microstructure and chemical composition of central and subsurface zone roll fragments are presented. The reason of destruction of experimental mill roll was discovered – nonconformance of roll material grade with the requirements of technological instructions and normative documentation for rough group of stands No. 1–3

Acute musculoskeletal neck and back pain

Back and neck pain is widespread in the population. Preferably, patients of working age are sick, which leads to serious economic losses. The transition of pain from acute to chronic increases financial costs, so effective treatment of back pain is an important medical, social and economic problem. Musculoskeletal pain (MSP) prevails among all types of back pain. The source of the MSP can be various structures of the musculoskeletal system: bones, joints, muscles, fascia, tendons, ligaments, intervertebral discs. The provoking factors for the development of the MSP are static and dynamic overloads arising from physical work, long stay in a fixed posture, unprepared movements, hypothermia, vibrations. The leading diagnostic method for the MSP is a physical research of a patient which includes a detailed collection of complaints and anamnesis, inspection in statics and dynamics, carrying out global and special tests, neuroorthopedic and neurological research. In most cases, the analysis of the results obtained allows you to set a clinical diagnosis without appointing additional research methods. Two cases of acute MSP with different localization, clinical manifestations and flow are offered to the discussion. In the first case, the process was localized in the muscles of the law back. In the second patient, the muscular tonic syndrome developed in the muscles of the neck and shoulder belt and was supported by functional blockades of the vertebral motor segments. For the treatment of both patients, NSAID, muscle relaxant, glucocorticoid, as well as non-drug therapy methods were used. For local injection therapy, a drug group of glucocorticoids was used, having a sodium phosphate and betamethazone dipropionate as part of the sodium betamethasone. The combination of two betamethazone salts provides both the rapid and prolonged effect of the drug, which makes it reasonable to use it with acute musculoskeletal pain.

Method for assessing the current and additional load on the parallel kinematic structure mechanisms electric drive system

Introduction. The problem of the load on an electric drive system in a parallel kinematic structure is considered. The task of developing a fault-tolerant system that provides performing a given process in case of a failure of one or more drives is described. The work objective is to create a method for estimating the current and additional load on each drive of the mechanism of a parallel kinematic structure. The solution enables to correct the operating mode when performing a given process without compromising serviceable drives.Materials and Methods. Previously, a diagnostic method was developed. It is based on the calculation and analysis of the coefficients of straight lines that approximate the envelopes of the values of the wavelet transform coefficients of electric motor current signals, taking into account the characteristic scales. This makes it possible to determine the current technical condition of the electric motor and find malfunctions. The logical continuation of this approach is the proposed method for assessing the current and additional load. It provides finding the current load on the drive based on the coefficients of the lines approximating the envelopes of the wavelet coefficients of the current signal. To calculate the additional load, the number and location of faulty drives are taken into account.Results. For each scale of the wavelet coefficients, the relative coefficients and the current load on each drive are determined. The possibility of redistributing the load to two adjacent jacks was checked; the behavior of the system in this case was investigated. The load moved by the faulty jack is redistributed to two adjacent jacks in equal shares — 14.76 % each. The total load on the drives is 44.28 %, which is safe for the servo. The load on the drive of the fourth jack does not change (29.52 %). The drives have a sufficient safety margin. It is established that all three operating modes are acceptable for the studied servo drive, and they do not cause dynamic overloads and premature failure.Discussion and Conclusions. The experimental studies on the method of assessing the current and additional load have shown its adequacy and high efficiency. It was found that when the drives were disconnected from one of the racks of the mechanism, the system performed a load redistribution on the drives. Thus, it was possible to avoid their dynamic overloads and premature failure. This means that the solution is able to ensure the reliable functioning of the complex at the time of renovation work.

The Investigation of Traffic and Near-Field Earthquake Loads Effects on the Nailed and Braced Excavations

Considering the statistical and probabilistic characteristics of construction conditions, the investigation of dynamic overloads' effects on the urban excavation wall is of great importance. In the present study, the performance of nailed and braced excavations under two vibrational dynamic excitations, traffic and near-field earthquake loads, have been investigated in four regions of Ahvaz. Critical boreholes with the lowest static bearing capacity have been selected by analyzing the layers' strength parameters in each region. Numerical models have been designed to limit the seismic waves' reflection at the excavation boundaries with 20 x 100 meters and with absorbing walls. Also, the damping ratio was assumed to be 2%. A harmonic wave at different speeds has simulated the excitation caused by the traffic passage. Resonant frequencies due to traffic induced vibration have been recorded in the speed range of 56 to 72 km/hr. Due to the traffic load, the bracing and the nailing systems showed less vertical and lateral displacements, respectively. Moreover, the excavations have been analyzed under ten acceleration with compatible near field characteristics of the Ahwaz plan acceleration (0.25g). The Kiyanpars region showed the highest vertical displacement difference between the two systems in the range of 0.032 m to 0.006 m. Due to earthquake loads, the bracing system showed less vertical displacement. The error of the analytical models' results in vertical displacement was 10% and 26% and in lateral displacement was 5% and 20% less than a nailed excavation located in the Kiyanpars region under traffic passage.

Recognition of LHD Position and Maneuvers in Underground Mining Excavations—Identification and Parametrization of Turns

The Inertial Measurement Unit (IMU) is widely used in the monitoring of mining assets. A good example is the Polish underground copper ore mines of KGHM, where research work with the use of the IMU has been carried out for several years. The potential of inertial sensors was ensured by the development of advanced analytics using machine learning methods to support the maintenance management of an extensive machine park and machine manufacturer in adapting various construction elements to mining conditions. The key algorithms developed in the field of inertial data concern: identification of cycles and components of the haulage process operations, identification of dynamic overloads, technical diagnostics of rotating elements, assessment of road conditions (bumps, slopes, damages), assessment of the technical condition of the pavement, assessment of the operator’s driving style, and finally the machine location in the mining excavation. One of the key operational contexts, necessary in the development of analytics for underground mining vehicles, is the identification of the turning moment of the machine at the intersection together with the determination of the driving direction and the turn angle. In the case of a mine with a room-and-pillar system, where the excavation system has the Manhattan structure, it is possible to use many simplifications to correctly estimate the machine motion path. The identification of the spatial context and the turning maneuver is of key importance both in the development of the machine location system, but also in multi-dimensional analyzes, including the analysis of dynamic overloads or the assessment of the operator’s driving style and work safety. The article presents a comparison of several mathematical models used for the machine turn detection problem, which were trained and tested on the real-life industrial data recorded using IMU during a single working shift of the self-propelled machine.

The influence of nonuniform heat transfer coefficient distribution on the value of thermal deformations in mechanical gas dynamic seal rings

Currently, many different aircraft engine types exist. They have a wide range of operating conditions: the flight speed can vary from zero to hypersonic values, the flight altitude from near-earth conditions to space flights. During the flight, loads are not kept constant. Engines have significant dynamic overloads, temperature and pressure differences, can operate in conditions of high humidity or dust, as well as in various aggressive environments. The development of aviation and rocket engine building is associated with a continuous increase in the working thermodynamical cycle parameters.Further improvement of gas turbine engines (GTE) can be carried out in two directions. The first is using new advanced engine designs based on a modernized cycle, with a different fuel, original design, and power scheme. This direction also includes the application of new high-performance elements in the engine: bearings, seals, coatings, etc. The second direction is related to the improvement of existing structures, increasing their efficiency by more detailed working conditions forecasting based on the use of modern computing software systems. This article presents a study of the potential mechanical face gas dynamic seal (FGDS) in the support in an aircraft engine compressor. Aircraft engines are characterized by multi-mode operation and high temperature levels in the internal cavities. For a FGDS operating with a working gap of several microns the exact determination of the deformation value is a very important result of the design process. This article considers the influence of the convective heat transfer coefficients distribution on the value of sealing rings thermal deformations. To achieve this goal, two compaction models were created: the gas-dynamic model for determining the convective heat transfer coefficients in the ANSYS CFX software program; and the structural model for calculating the resulting deformations. Interaction between the models was performed based on a specially created methodology. The obtained results can be used in the design of a FGDS for the supports in the compressors of aircraft engines and power plants.

Organization of safe execution of works with the use of trapping nets

The organization of ensuring safe execution of building and assembly works when erecting and reconstructing buildings (structures) of various purposes based on the application of trapping nets to prevent industrial injuries in case of human or items falling from height is presented. Structural layout of a safety (catching) device with pivotally mounted brackets and a freely hanging net was considered. Appearing dynamic loads in case of items falling on trapping nets depending on impact acceleration were theoretically identified. It was found out that a trapping net with pivotally positioned brackets additionally reduces deceleration loads in relation to devices with rigidly fixed brackets and their use is more effective for cases of men falling with insignificant forward velocity. Bench and shop tests of trapping devices were carried out with the purpose of checking compliance of selected theoretical models, selection of developed options of designs and schematic diagrams, differentiation of reaction of capron and lavsan net materials from action of impulse loads. Test key results confirming matching of experimental data with presented theoretical models were showed. It was established that dynamic overloads depend both on a bracket position angle as well as on a place of an item falling into net, the value of pitch of deflection of net cloth made of lavsan and capron materials is almost similar and characteristics of values of their displacement under dynamic loads from a falling item are identical.

Organization of safe execution of works with the use of trapping nets

The organization of ensuring safe execution of building and assembly works when erecting and reconstructing buildings (structures) of various purposes based on the application of trapping nets to prevent industrial injuries in case of human or items falling from height is presented. Structural layout of a safety (catching) device with pivotally mounted brackets and a freely hanging net was considered. Appearing dynamic loads in case of items falling on trapping nets depending on impact acceleration were theoretically identified. It was found out that a trapping net with pivotally positioned brackets additionally reduces deceleration loads in relation to devices with rigidly fixed brackets and their use is more effective for cases of men falling with insignificant forward velocity. Bench and shop tests of trapping devices were carried out with the purpose of checking compliance of selected theoretical models, selection of developed options of designs and schematic diagrams, differentiation of reaction of capron and lavsan net materials from action of impulse loads. Test key results confirming matching of experimental data with presented theoretical models were showed. It was established that dynamic overloads depend both on a bracket position angle as well as on a place of an item falling into net, the value of pitch of deflection of net cloth made of lavsan and capron materials is almost similar and characteristics of values of their displacement under dynamic loads from a falling item are identical.

Transformer Thermal Capacity Estimation and Prediction Using Dynamic Rating Monitoring

Dynamic rating monitoring is a solution to face challenges in both the operation and the planning of power systems. With thermal monitoring, dynamic overloads of transformers are allowed; however, the thermal model used to predict hot-spot must be capable of ensuring the assessment of insulation life expectancy. Hence, this paper presents an online algorithm to estimate and predict transformers’ rating in order to assess the overload capability during short and long times. The overload factors are computed using estimations of top-oil temperature. The main characteristic of this proposal is that the environmental cooling conditions are considered by the fitting of the parameters of a simple equivalent thermal circuit using an extended Kalman filter during the transformer operation. To validate the implementation of the algorithm, the information provided by typical transformer rating monitoring systems is used. Thus, the performance and effectiveness of the algorithm are verified using field measurement data during the normal operation of two power transformers.

Amplification Factors in the Case of Beam Under Moving Force – Theoretical Analysis

AbstractThe impact of a moving load speed on the dynamic overload of beams, assuming that the track of the load has no unevenness, is examined. First the problem of a visco-elastic beam on a Winkler foundation subjected to a force moving at a constant speed will be solved. Using the Bubnov-Galerkin method, the deflections of the beam, and then the bending moments and shear forces will be determined. The solution of the problem will be obtained both for the case of a forced vibration and the case of a free vibration after the moving force has left the beam. Using these solutions, dynamic amplification factors will be determined for the deflections, bending moments, and shear forces, which are different for the two cases.The magnitude of the amplification factors increases and decreases alternately as a function of the speed. In the case of a single force on a beam, the dynamic overloads are limited, and do not exceed 60%. There is no resonance phenomenon in the beam subjected to the single moving force. The dynamic amplification factors determined in this way can be used as correction coefficients when designing engineering structures subjected to moving loads by static methods.

THE PARACHUTE SYSTEM WITH THE ELASTIC LINK AND THE LOAD DIVIDED INTO TWO PARTS AS A TANDEM

The article suggests a new type of the parachute system (PS). Its distinctive feature is the presence of an elastic link (EL) for attaching the cargo to the parachute, and the cargo itself is divided into two parts, m1 and m2, comparable in weight and suspended one under the other. The cargo is connected by a cable through the cable length control mechanism. PS in flight consists of a parachute, stretched EL, cargo m1, the cable length control mechanism, cable, cargo m2. The main feature of this type of PS is the ability to provide low dynamic overloads of m1 cargo during the entire flight, including landing. For a soft landing of m1 cargo, it is necessary to choose the main parameters of the PS correctly: the parachute area, the EL stiffness, the weight of m1 and m2 cargo, the length of the cable. To confirm the efficiency and feasibility of the proposed concept, an experimental PS with a flight mass of m ≈ 10 kg was designed, prepared and tested. The parachute is made of zero porosity fabric, its area is S = 2.2 m2 It has a cylindrical skirt that is used to give stability to the PS in flight. As an EL a silicone tube is used with the length of l0 = 6 m when unstretched, but in flight under the weight of cargo ml and m2 it is stretched to l0 + Δl ≈ 17 m. The mass of the cargo ml is m1 - 5.5 kg, m2 cargo has a mass of m2 ≈ 4.5 kg. To raise the PS a two-seat hang-glider was used. The drop occurred from the height of H ≈ 200 m. The rate of decent before landing was Ve = 8...9 m/s. The analysis of the final records of dynamic overloads shows that during the entire flight, including landing, the total cargo overload ml did not exceed n = 5. Thereby operability, feasibility and the declared properties of the offered type of PS are confirmed.