Medium Load Research Articles

Evaluation of bearing capacity of reinforced concrete box ribbed arch bridge based on static load test

In order to evaluate the stress and working performance of a reinforced concrete box-ribbed arch bridge after completion, the load test of the bridge is carried out. Static load test is to test the stress and displacement of each section of arch rib under the action of partial load and medium load. Through the experiment with the key parts of the stress (strain) and displacement load and other important data, through analysis and study, the comprehensive analysis of the phenomenon of calculation and test, a comprehensive performance evaluation structure and function whether meet the design requirements, to provide technical basis for the safety of the bridge operation, and provide the original material for the bridge maintenance and management in the future.

Study on static load test of modified and extended rigid frame bridge

In order to evaluate the mechanical condition and working performance of a rigid frame bridge after reconstruction and extension, the mechanical performance of the bridge was analyzed by static load test. Static load test is the test of stress at each section of main beam under the action of partial load and medium load. The results show that, under the action of each load, the check coefficient of strain and deflection at each measuring point of the box girder does not exceed the standard limit value 1, the relative residual strain or deformation at each measuring point does not exceed the standard limit value 20%, the stress condition of the tested section of the box girder is normal, and the structure is under the normal stress state under the action of the test load.

Investigation on Dynamic Characteristic of Geared Rotor System Composed of Ultrahigh Molecular Polyethylene Gear and Metal Gear

A geared rotor system model consisting of UPE gears and steel gears for medium speed, medium load and long servo time is proposed. The solid models of steel-steel, steel-UPE and UPE-UPE gear systems were established. The dynamic models of steel-UPE gear system and UPE-UPE gear system were reconstructed by using the theoretical mechanical model of UPE. The time-varying meshing stiffness of three gear systems is analyzed. The vibration responses of three gear systems are studied by STFT method. The dynamic loads of three gear systems under different loads and rotational speeds are researched in detail, and the changing rules of dynamic loads of three gear systems under different loads and rotational speeds are revealed. At last, the first ten modes of three gear systems are calculated and the results are discussed. At the same time, the modal results are used to verify the correctness of the research on vibration response and dynamic load of three gear systems.

Dynamic load test and lateral load distribution of a modified rigid frame bridge

In order to evaluate the stress state and working performance of a rigid frame bridge after reconstruction and extension, load test and transverse load distribution were carried out. Static load test is the test of stress at each section of main beam under the action of partial load and medium load. Dynamic load test is used to test the inherent fundamental frequency, damping ratio and impact coefficient of the bridge through pulsation test and sports car test. The results show that the first order vibration of the bridge is mainly transverse vibration from the measured modal parameters, which is consistent with the characteristics of higher pier and greater flexibility. The vibration characteristics of the bridge structure are low frequency and small damping vibration, the value of which belongs to the normal range among similar bridge structures, the overall stiffness of the bridge structure is normal, and the measured impact coefficient during the test of sports car is less than the design impact coefficient, indicating that the dynamic stiffness of the bridge meets the design and specification requirements.

A Weighted Combination Forecasting Model for Power Load Based on Forecasting Model Selection and Fuzzy Scale Joint Evaluation

To solve the medium and long term power load forecasting problem, the combination forecasting method is further expanded and a weighted combination forecasting model for power load is put forward. This model is divided into two stages which are forecasting model selection and weighted combination forecasting. Based on Markov chain conversion and cloud model, the forecasting model selection is implanted and several outstanding models are selected for the combination forecasting. For the weighted combination forecasting, a fuzzy scale joint evaluation method is proposed to determine the weight of selected forecasting model. The percentage error and mean absolute percentage error of weighted combination forecasting result of the power consumption in a certain area of China are 0.7439% and 0.3198%, respectively, while the maximum values of these two indexes of single forecasting models are 5.2278% and 1.9497%. It shows that the forecasting indexes of proposed model are improved significantly compared with the single forecasting models.

К экологии эвритрофных дереворазрушающих грибов Fomes fomentarius (L.) Fr. и Fomitopsis pinicola (Sw.) P. Karst. в Красноярске и его окрестностях

This paper is devoted to the review of the environmental and trophic characteristic features of eurytrophic wood-destroying fungi in Krasnoyarsk and its nearest suburbs in habitat conditions with various anthropogenic loads. The research covered forest stand within the green areas of the city (including islands of the Yenisei River), forest areas at the outskirts of the city and in «Stolby» state nature reserve. The research included two species of tinder fungus widely spread in the Northern hemisphere: Fomes fomentarius (L.) Fr. (confined to various hardwoods, mostly birch) and Fomitopsis pinicola (Sw.) P. Karst. (confined to trees of various species). Both species of fungi are facultative parasites. The research showed that these species of fungi use quite a restricted set of host substrates showing a pretty narrow range of trophic preferences, despite the presence of numerous species of trees suitable for them at the surveyed area. F. fomentarius uses birch, poplar and aspen as a substrate within the researched area. It is very rarely found at other wood species. The trophic range of the highly eurytrophic species F. pinicola is represented here mostly by a few coniferous species, such as pine, fir and spruce tree. This fungus is present at birch trees and aspen much more rarely. These species of tinder fungi were not found at other wood species of the surveyed area. F. fomentarius is very often found at birches in the areas with minimal anthropogenic load (in «Stolby» nature reserve) and becomes less numerous with the increasing manthropogenic load. The situation is the contrary with poplar: F. fomentarius is rarely found at poplar in the areas with low or medium anthropogenic load, but often destroys poplar wood in the areas with the increased anthropogenic load (within the green space of urban areas). Moreover, F. fomentarius is often found in parklands, rather than along the roadside lanes. F. pinicola is typical for ecosystems with low anthropogenic load and prefers coniferous wood species. It is mostly found in ecosystems of “Stolby” natural reserve, mainly on fir and pine species.

A Cooperative Online Learning-Based Load Balancing Scheme for Maximizing QoS Satisfaction in Dense HetNets

This paper proposes a cooperative multi-agent online reinforcement learning-based (COMORL) bias offset (BO) control scheme for cell range expansion (CRE) in dense heterogeneous networks (HetNets). The proposed COMORL scheme controls BOs for CRE to maximize the number of user equipments (UEs) that satisfy their quality of service (QoS) requirements, especially in terms of delay and data rates. For this purpose, we developed a QoS satisfaction indicator that measures a violation of delay requirements by considering both QoS requirements and signal-to-interference-plus-noise ratio (SINR). In addition, we formulated a Markov decision process (MDP) model that is solved with a cooperative multi-agent online reinforcement learning algorithm. The proposed COMORL scheme maximizes the global utility for load-coupled base stations. Our simulation results verify the proposed COMORL scheme’s effectiveness in terms of throughput, delay satisfaction ratio, and fairness. Specifically, we verify that the proposed COMORL scheme achieves a maximum of approximately 27% and 30% improvement of the delay satisfaction ratio, which is how many UEs satisfy their delay requirement among all of the UEs in a serving BS under medium and full traffic loads, respectively, in a dynamic scenario in comparison to the max-SINR scheme.

Современное состояние и перспективы развития газотранспортной сети Ангарского городского округа

The aim of the research is to analyse the status of the low-pressure gas distribution system functioning in of the Angarsk urban district (AUD), as well as to identify possible directions for its reconstruction and modernization. These measures are aimed at developing the housing stock and the capacity of industrial enterprises. The number of local and distributed consumers in Angarsk and the Angarsk urban district was used to analyse the current load of medium- and low-pressure gas supply systems. To check the status of the gas supply system in the region, a theoretical study was undertaken involving analysis, abstraction, and induction. Choosing the methods for reconstruction and modernization of the system required abstraction from the current gas type used in the AUD. Particular attention was drawn to the forecast of gas consumption in the next 10–20 years and possible gasification of the Irkutsk region due to the launch of the main gas pipeline "Power of Siberia". The conducted analysis of the current status of the gas distribution system revealed shortcomings, indicating the need for reconstruction and modernization of network sections, as well as control and regulation units. In addition, the reliability of the operating equipment was checked, considering its service life. The data obtained were used to develop guidelines for reconstructing the existing gas distribution systems and modernizing control units and gas equipment both technically and economically. An increasing volume of gas consumption by the housing stock and the industrial sector compels us to seriously consider the reconstruction of the gas supply system. However, it is essential to develop a gas supply system that accounts for the possibility of transition to natural gas. This factor calls for the project solutions to be compatible with any type of gas fuel.

A novel gate driver for Si/SiC hybrid switch for multi‐objective optimization

A novel gate driver with simple functional and structural integration is proposed here, which splits the input gate signal and outputs two separate signals with a dedicated delay time to drive the two constitutional switches, aiming at the cost-effectiveness and power loss reduction of the Si/SiC hybrid switch. The dependency of the hybrid switch's thermal and efficiency performance on the parameters of the gate driver are theoretically and experimentally investigated in a 9 kW 20 kHz Si/SiC hybrid switch based boost converter. A novel load current dependent gate control strategy is proposed to be implemented in the proposed gate driver to achieve the high conversion efficiency under light to medium load condition and balanced junction temperature between the two internal devices under heavy load conditions. The experimental results based on a 20 kHz boost converter show that the Si/SiC hybrid switch with the novel gate driver and optimal current dependent control strategy offers a 163% and 10% rise in power handling capability, respectively, compared to that using the all-IGBT device and all-SiC MOSFET device, and yet a considerably lower device cost.

Influence of Parthenium Hysterophorus and Impomea Pes-caprae Fibers Stacking Sequence on the Performance Characteristics of Epoxy Composites

ABSTRACT The application suitability of natural fibers is increased by the method of hybridization. The current study deals with the development and characterization of four different tri-layer composites by varying the stacking sequence of Parthenium hysterophorus and Impomea pes-caprae fibers with epoxy as a matrix, by using the conventional hand layup process. The mechanical properties, namely tensile, flexural, impact, Shore D hardness, and water absorption properties, were analyzed as per ASTM. The test results show that composites with upper layers of Impomea pes-caprae and a core layer of Parthenium hysterophorus fibers showed enhanced mechanical properties and reduced water absorption, thereby proving its suitability for lightweight medium load applications. Morphological studies using Scanning Electron Microscope elucidated the fiber bonding and void characteristics of the tested composites.

Effects of fuel blending on first stage and overall ignition processes

The effects of blending ratio on mixtures of an alcohol-to-jet (ATJ) fuel and a conventional petroleum-derived fuel on first stage ignition and overall ignition delay are examined at engine-relevant ambient conditions. Experiments are conducted in a high-temperature pressure vessel that maintains a small flow of dry air at the desired temperature (825 K and 900 K) and pressure (6 MPa and 9 MPa) for fuel injections from a custom single-hole, axially-oriented injector, representing medium (7.5 mg) and high (10 mg) engine loading. Formaldehyde, imaged using planar laser-induced fluorescence, is measured at discrete time steps throughout the first and second stage ignition process and is used as a marker of unburned short-chain hydrocarbons formed after the initial breakdown of the fuel. The formaldehyde images are used to calculate the first stage ignition delay for each ambient and fuel loading condition. Chemiluminescence imaging of excited hydroxyl radical at 75 kHz is used to determine the overall ignition delay. At all conditions, increased volume fraction of ATJ resulted in longer, but non-linearly increasing, overall ignition delay. Across all of the blends, first stage ignition delay accounted for about 15% of the increase in overall ignition delay compared to the military's aviation kerosene, F-24, which is Jet A with additives, while extended first stage ignition duration accounted for 85% of the increase. It is observed that blends consisting of 0–60% by volume of the low cetane number ATJ fuel produced nearly identical first stage ignition delays. These results will inform the development of ignition models that can capture the non-linear effects of fuel blending on ignition processes.

Wireless Non-Destructive Moisture Content Characterization of Trees by Highly-Sensitive Compact Resonating Probes

Monitoring the moisture content (MC) of trees and plants by a non-destructive and wireless methodology is an essential effort towards the early diagnostics and prevention of forest fires. This work presents a MC sensing system comprising a nested split-ring resonator (NSRR) probe — a structure which has been demonstrated to be superior to the traditional SRRs in terms of its sensitivity and compactness — and an antenna to illuminate it. The NSRR is attached to the plant and the near-field interaction between the NSRR and the antenna produces an electromagnetically coupled system whose resonance frequency ( ${f}_{\textit {res}}$ ) is modified by the water content of the medium loading the NSRR. Full-wave simulations are performed to model the system response for different tree species. Results of the experiments conducted in vitro and in vivo are presented. In the in vitro experiments, a freshly cut tree branch sample is allowed to dry at ambient temperature and its MC change is monitored by the system. The in vivo experiments prove that the sensing system can also capture the dynamic MC change of a plant. Calibration sets generated by curve-fitting of the variation of ${f}_{\textit {res}}$ with respect to the MC and other sensing parameters are used to transform the measured ${f}_{\textit {res}}$ to MC information. The results of the simulations and the experiments demonstrate that the proposed sensing system can be utilized as a non-destructive and wireless method for highly-sensitive characterization of the MC of trees and plants.

A Study on the High Load Operation of a Natural Gas-Diesel Dual-Fuel Engine

Diesel fueled compression ignition engines are widely used in power generation and freight transport owing to their high fuel conversion efficiency and ability to operate reliably for long periods of time at high loads. However, such engines generate significant amounts of carbon dioxide (CO2), nitrogen oxides (NOx), and particulate matter (PM) emissions. One solution to reduce the CO2and particulate matter emissions of diesel engines while maintaining their efficiency and reliability is natural gas (NG)-diesel dual-fuel combustion. In addition to methane emissions, the temperatures of the diesel injector tip and exhaust gas can also be concerns for dual-fuel engines at medium and high load operating conditions. In this study, a single cylinder NG-diesel dual-fuel research engine is operated at two high load conditions (75% and 100% load). NG fraction and diesel direct injection (DI) timing are two of the simplest control parameters for optimization of diesel engines converted to dual-fuel engines. In addition to studying the combined impact of these parameters on combustion and emissions performance, another unique aspect of this research is the measurement of the diesel injector tip temperature which can predict potential coking issues in dual-fuel engines. Results show that increasing NG fraction and advancing diesel direct injection timing can increase the injector tip temperature. With increasing NG fraction, while the methane emissions increase, the equivalent CO2emissions (cumulative greenhouse gas effect of CO2and CH4) of the engine decrease. Increasing NG fraction also improves the brake thermal efficiency of the engine though NOx emissions increase. By optimizing the combustion phasing through control of the DI timing, brake thermal efficiencies of the order of ∼42% can be achieved. At high loads, advanced diesel DI timings typically correspond to the higher maximum cylinder pressure, maximum pressure rise rate, brake thermal efficiency and NOx emissions, and lower soot, CO, and CO2-equivalent emissions.

Comparison of tribology performance, particle emissions and brake squeal noise between Cu-containing and Cu-free brake materials

The present study developed two Cu-free brake materials using carbon fiber or carbon nanotube as the replacements for copper fiber and evaluated their tribology performance, particle emissions and brake squeal noise. Results show that the coefficients of friction (COFs) of the Cu-free brake materials are lower than that of Cu-containing brake material at the braking conditions with low and medium loads. At the high load braking condition, all the braking materials exhibit comparable COFs. Cu-free brake materials present larger specific wear rates than the Cu-containing brake material. However, the application of carbon fiber can reduce the particle number emission. All brake materials exhibit comparable brake squeal noise.

Can a metric combining arm elevation and trapezius muscle activity predict neck/shoulder pain? A prospective cohort study in construction and healthcare

ObjectiveTo determine whether a composite metric of arm elevation and trapezius activity (i.e. neck/shoulder load) is more strongly associated with the 2-year course of neck and shoulder pain intensity (NSPi) among construction and healthcare workers than each exposure separately.MethodsDominant arm elevation and upper trapezius muscle activity were estimated in construction and healthcare employees (n = 118) at baseline, using accelerometry and normalized surface electromyography (%MVE), respectively. At baseline and every 6 months for 2 years, workers reported NSPi (score 0–3). Compositions of working time were determined for arm elevation (< 30°; 30–60°; > 60°), trapezius activity (< 0.5%; 0.5–7.0%; > 7.0%MVE), and a composite metric “neck/shoulder load” (restitution, low, medium, and high load). Associations between each of these three compositions and the 2-year course of NSPi were determined using linear mixed models.ResultsAssociations between exposure compositions and the course of NSPi were all weak and in general uncertain. Time spent in 0.5–7.0%MVE showed the largest and most certain association with changes in NSPi during follow-up (β = − 0.13; p = 0.037; corresponding to a −0.01 change in NPSi every 6 months). Among pain-free workers at baseline, medium (β = − 0.23; p = 0.039) and high (β = 0.15; p = 0.031) neck/shoulder load contributed the most to explaining changes in NSPi.ConclusionThe composite metric of neck/shoulder load did not show a stronger association with the course of NSPi than arm elevation or trapezius activity alone in the entire population, while some indications of a stronger association were found among those who were pain-free at baseline.

Design of arduino-based loading management system to improve continuity of solar power supply

&lt;p&gt;Solar power plants using environmentally friendly technology in the process of harvesting energy from the sun can be a solution to the future electricity crisis so that it has been the most widely developed and reliable alternative. However, the conversion of solar energy depends on the availability and conditions of sunlight. In sunny conditions, the PV system can serve large loads while charging the battery to the maximum. While in cloudy weather conditions or at night, the PV system serves the load and without charge of the battery. The battery will discharge the stored energy until it runs out, and the supply to the load will be cut off before the desired time. Therefore, research on the PV system loading management system is needed to increase the amount of electricity from solar energy and maintain the continuity of electricity supply to the load. The load power management strategy follows the conditions of sunny, cloudy, rainy, or night time by considering the remaining capacity of the battery that can be used. Load installations are designed to consist of low, medium, and high load installations. Simulation results show that the use of PV loading management strategies can increase the operating time of the PV system. When the remaining less than 10% battery capacity and PLN supply is available, the supply will be switched to PLN. The remaining 10% of PV battery capacity could be used to maintain electricity supply to a low load if the PLN supply interrupted. Thus, the use of a loading management strategy will increase the electricity supply from renewable energy and improve the sustainability of electricity supply.&lt;/p&gt;

A numerical investigation on the effects of gaseous fuel composition in a pilot ignited direct injection natural gas engine

Pilot ignited direct injection natural gas engines have the potential to obtain both high efficiency and low emissions, thus, are considered as promising alternations for diesel engines. In order to assess the effects of gaseous fuel composition on this type of engines, a three-dimensional model was constructed based on a new mechanism developed for the high-precision prediction of soot precursors. The numerical results showed that thermal efficiency could be improved by increasing nitrogen proportion at medium and high loads as well as increasing propane proportion at low load. Regarding emissions, it was found that ethane addition will lead to deteriorated NOx and CO emissions at high and medium loads along with increases in soot emissions at all loads. When propane is blended, though notable increased NOx emissions and higher soot emissions could be observed at all loads, improved CO emissions are revealed at high load with small blending ratios and at low load with all blending ratios. In contrast to ethane and propane addition, nitrogen addition is favorable for NOx control at all engine loads and is beneficial for soot control at high and medium loads. CO emissions, however, will suffer from nitrogen addition at high and low loads.

Kadmiumstressz detektálására alkalmazható in situ és destruktív mérési módszerek összehasonlító vizsgálata búzán

The effects of cadmium (Cd) stress and arbuscular mycorrhizal fungus (AMF) inoculation were investigated in wheat [Triticum aestivum L. cv. TC-33] under controlled conditions. The experiments aimed to reveal what stress responses belong to the different levels of Cd load in the growth medium (0; 1; 2,5 and 5 mg Cd kg-1 substrate). To detect the effect of Cd stress, we compared plant physiological and growth indicators measured with both in situ and destructive methods. Electrical capacitance (CR) was evaluated during the experiments as a method to indicate stress responses through of Cd-induced root system changes.During the growth period, the photosynthetic activity (Fv/Fm), the chlorophyll content index (CCI) of the leaves, and the CR of the root-soil system were monitored in situ. After harvest, the membrane stability index (MSI), the cadmium and phosphorus concentrations of the plants, the root dry mass (RDM), the shoot dry mass (SDM) and the leaf area (LA) were measured. The root colonization of AM fungi was estimated by microscopic examination. Data matrices were evaluated with principal component analysis (PCA) which had been proved to be a good statistical method to the sensitivity between measurement methods.Taking all parameters into account in the PCA, a complete separation was found between the contaminated and non-contaminated variants along the main component PC1. The measured values of the Cd1 treatment sometimes overlapped with that of control plants, but differed from that of the Cd2 and Cd3 doses. The parameters well reflected that AMF inoculation alleviated the stress caused by Cd. PCA shows a visible effect of AM, but the separation between mycorrhizal and non-mycorrhizal plants is weaker than that between Cd contaminated and non-treated ones. The Cd stress significantly decreased the Fv/Fm, CCI, CR, SDM, RDM and LA. The CR and growth parameters proved to be the best indicators to characterize the Cd phytotoxicity in the TC-33 wheat cultivar.

Influence of the addition of titanium oxide nanoparticles to Fischer-Tropsch diesel synthesised from coal on the combustion characteristics and particulate emission of a diesel engine

The use of Fischer–Tropsch (F–T) diesel synthesised from coal in automobiles can alleviate petroleum shortages and promote clean utilisation of coal. Because F–T diesel does not contain oxygen, in this study, we added TiO2 nanoparticles and n-octanol to the F–T diesel to serve as oxygenated enhancers to increase the oxygen content and reduce the particulate matter emission of F–T diesel. To achieve better combustion characteristics and emission performance, TiO2 nanoparticles with different concentrations (20, 50, and 100 ppm) were dispersed to the fuel blends of F–T diesel and n-octanol to determine the optimum amount of TiO2 nanoparticles. The brake thermal efficiency (BTE), combustion stability, number concentration, and size distribution of the ultrafine particulate (UFP) emission of the three nano-emulsion fuels were investigated on a turbocharged heavy-duty diesel engine. The experimental results indicated that the BTE of the F–T diesel and that of the nano-emulsion fuel T50 increased by 0.75 % and 2.26 %, respectively, compared with petro-diesel. The nano-emulsion fuels had higher peak cylinder pressure and peak heat release rate owing to the faster combustion rate caused by the micro-explosion of fuel droplets and higher thermal conductivity caused by the high surface-to-volume ratio of TiO2 nanoparticles. Moreover, the nano-emulsion fuels exhibited higher cyclic variations of peak cylinder pressures and more dispersed corresponding crank angles with the increase in the concentration of TiO2 nanoparticles. Compared with petro-diesel, the soot emission of the F–T diesel was reduced by an average of 27.32 % at various loads, whereas that of the optimal T50 decreased by an average of 43.61 %. Additionally, the number concentration of UFPs of T50 was reduced by an average of 21.2 % compared to the F–T diesel. At low loads, the three nano-emulsion fuels exhibited greater geometric mean diameters (GMDs) of UFPs and lower ratios of nucleation mode particulates (NMPs) owing to the higher fuel viscosity in the pre-injection stage at a lower in-cylinder temperature. At medium and high loads, the nano-emulsion fuels exhibited smaller GMDs of UFPs and higher ratios of NMPs owing to micro-explosion and secondary atomisation at higher temperatures.

Effect of Strain Rates on Failure of Mechanical Properties of Lumbar Intervertebral Disc Under Flexion.

ObjectiveTo evaluate the strain‐rate‐dependent viscoelastic properties of the intervertebral disc by in vitro experiments.MethodThe biomechanical experiments were conducted from September 2019 to December 2019. The lumbar spines of sheep were purchased within 4–6 hours from the local slaughterhouse, and the intervertebral disc samples were divided into three groups. In rupture group, the samples were used to test the mechanical behavior of the intervertebral disc rupture at different strain rates. In fatigue injury group, the samples were used to test the mechanical behavior of fatigue injury on the intervertebral disc under different strain rates. In internal displacement group, the samples were used to test the internal displacement distribution of the intervertebral disc at different strain rates by applying an optimized digital image correlation (DIC) technique.ResultsBoth the yielding and cracking phenomenon occurs at fast and medium loading rates, while only the yielding phenomenon occurs at a slow loading rate. The yield stress, compressive strength, and elastic modulus all increase with the increase of the strain rate, while the yield strain decreases with the increase of the strain rate. The logarithm of the elastic modulus in the intervertebral disc is approximately linear with the logarithm of the strain rate under different strain rates. Both before and after fatigue loading, the stiffness in the loading and unloading curves of the intervertebral disc is inconsistent, forming a hysteresis loop, which is caused by the viscoelastic effect. The strain rate has no significant effect on the internal displacement distribution of the intervertebral disc. Based on the experimental data, the constitutive relationship of the intervertebral disc at different strain rates is obtained. The fitting curves are well coupled with the experimental data, while the fitting parameters are approximately linear with the logarithm of the strain rate.ConclusionsThese experiments indicate that the strain rate has a significant effect on the mechanical behavior of the intervertebral disc rupture and fatigue injury, while the constitutive equation can predict the rate‐dependent mechanical behavior of lumbar intervertebral disc under flexion very well. These results have important theoretical guiding significance for preventing lumbar disc herniation in daily life.