Constant Load Research Articles

Optimization of low-temperature multi-stage submersible pump based on blade load

The multi-stage submersible pump is a power conveyor for low-temperature media, which is conveyed by the rotating of centrifugal impellers. In this study, the impellers of a multi-stage submersible pump were optimized to improve the efficiency under the premise of the constant total blade load and head. Based on the analysis of performance and flow for each stage of the 18-stage submersible pump, the optimization scheme composed of the first stage, the middle stage, and the last stage was determined. The blade outlet angle, average blade wrapping angle, and blade wrapping angle difference were selected as optimization parameters through Plackett–Burman experimental design and significance analysis, and the blade profile was redrawn by changing the blade load distribution. The performance prediction model was built based on the Kriging response surface model, and then, the global optimal blade profile was found by non-dominated Sorting Genetic Algorithm II. The efficiencies of the 3-stage submersible pump and 18-stage submersible pump with optimized impeller increased by 2.35% and 2.01%, respectively. Under the design condition, the flow rate loss and pressure pulsation at the impeller outlet decreased and the stator–rotor interaction between the impeller and guide vane was weakened. This will lead to a reduction in unstable flow such as secondary flow and vortices, and an improvement of flow stability at the impeller outlet.

OPTIMISED DAMPING CONTROL OF ISLANDED DC POWER SYSTEMS USING STATE FEEDBACK

DC microgrid contains a large number of tightly regulated closed-loop converters, which performance for the constant power loads and may cause stability problem of bus voltage when used as a load since they trend to draw constant power. In order to improve the stability of DC microgrid, this paper proposes a method for stabilization the DC microgrid based on the state feedback. e. In this study, the small disturbance linearised state equation of a DC-power grid with constant power load is derived to estimate the damping characteristics of DC voltage. To enhance the transient voltage stability, a novel DC- voltage damping control method is proposed, where both DC voltage and DC current are used as state feedback variables. Index Terms – DC microgrid; stabilization; islanded mode; constant-power load; PID controller

Maximum Sensitivity Constrained Graphical Controller Tuning for a DC–DC Boost Converter Loaded With a CPL

Owing to the negative impedance instability of the constant power load (CPL), oscillations are induced in the output voltage of the boost converter which may lead to voltage collapse. This paper proposes a graphical strategy to tune a PID controller for the boost converter loaded with a CPL. The idea of root crossing boundaries is applied to compute the all stability region. Robustness and relative stability of the system are addressed by obtaining the desired maximum sensitivity region (DMSR) within the all stability region. Required controller parameters are obtained by finding the centroid of the DMSR. A novel technique to select the derivative gain of the PID controller from the trade-off curve between disturbance rejection and noise suppression abilities, is also proposed. Experimental results with comparison are provided to show the effectiveness of the presented scheme.

Calculation of Magnetic Losses with Non-Uniform Distribution of Magnetic Induction in the Stator Tooth of a Switched Reluctance Motor

The aim of this study is to investigate and determine the effect of accounting for the non-uniform distribution of magnetic induction (by detailing the stator tooth model) on the calculation results of magnetic losses in the stator teeth of a switched reluctance motor in quasi-steady-state modes. To achieve this goal, dependencies of phase flux linkage, electromagnetic torque of the motor, and additionally, dependencies of the root mean square values of magnetic inductions in stator tooth elements on the rotor angle and current have been determined using the finite element method. An investigation of dynamic modes of the switched reluctance motor based on an improved simulation model has been conducted at various values of constant load torque. Dependencies of magnetic inductions over time for each stator tooth element for the studied quasi-steady-state operating modes have been obtained. Magnetic losses have been calculated, taking into account the maxima of the temporal dependencies of root mean square values of magnetic induction in stator tooth elements. The most important outcome is a quantitative assessment of the influence of the non-uniform distribution of magnetic induction on the calculated value of magnetic losses based on the detailing of the stator tooth model in the operational modes of the switched reluctance motor compared to the traditional approach. The significance of the work lies in developing an approach to refining the calculation of magnetic losses by considering local saturation in the magnetic circuit during the operation of the switched reluctance motor.

Comparison of stress relaxation properties between 3-dimensional printed and thermoformed orthodontic aligners: A pilot study of in vitro simulation of two consecutive 8-hours force application

Objectives: The study is aimed to examine the stress relaxation of 3d-printed aligners, Tera Hartz TC-85 (Graphy Inc. Seoul, South Korea) and Polyamide (Noxi, Sweden and Martina, Due Carrare, Padova, Italy), in comparison to thermoformed aligners, Zendura FLX (Bay Materials LLC, Fremont, California, USA) and Duran (SCHEU, Iserlohn, Germany). Material and Methods: A stress-relaxation test was conducted using a motorized vertical testing bench, TVO-S (AstraLab, Mariano Comense, Italy), applying a constant and controlled pre-set load. Each sample was subjected to a deflection of 0.5 mm while being immersed in water for eight consecutive h at a constant temperature of 37°C. During this period, data were collected at intervals of 1 s. The same test was repeated twice (test 1 and test 2) on the same specimen, in order to simulate the intermittence of deflection force. Results: For both Test 1 and Test 2, a total of 28,800 measurements were recorded for each aligner, with one measurement taken per second over a duration of 8 h/test. A statistically significant difference (P < 0.001) was found for all materials and at all time periods were considered. If the percentage of stress relaxation is considered, a significant difference among the four aligners was found as well. Conclusion: All materials displayed substantial stress decay during the 8-h period of constant load, although significant differences were observed among the various materials under investigation. The Noxi aligner demonstrated the highest force values in both tests, confirmed by low percentages of stress relaxation ranging from 23% to 32%.

Confronting combined cyber-attacks on collaborative DC microgrids using a communication protocols-based distributed unscented Kalman filter

The functioning of microgrids (MGs), which represent a contemporary arrangement of distribution networks featuring local control over generation and consumption, necessitates telecommunication infrastructure for transmitting and receiving measurement data and control commands. This reliance on telecommunication infrastructure renders MGs vulnerable to the threat of cyber-attacks. The existing methods for identifying cyber-attacks have been restricted solely to MG modeling. However, identifying and restoring a cyber-attack lack dependability and feasibility in a practical application without the concurrent modeling of MGs and their communication protocols. Therefore, this study aims to identify hybrid cyber-attacks (simultaneous false data injection and time delay attacks) to flow sensors and cyber links in direct flow MGs by considering the communication protocols between them, as well as extracting and reconstructing real measurement data. In order to achieve this objective, a generalized unscented Kalman filter (UKF) is introduced in conjunction with communication protocols incorporating an augmented state space to estimate the power of nonlinear loads. For this purpose, two measurement models have been developed to prevent data collisions and reduce the communication load. These models are based on the round-robin scheduling protocol and the try-once-discard weighted protocol. They aim to establish a specific order for data transfer from sensors to the filter. The article concludes by presenting a stability analysis of the protocol-based generalized UKF, which aims to ensure the convergence and limitation of the estimation error. The study presents simulation results on the resilient reconstruction of hybrid cyber-attacks involving unknown constant power loads and noise. The proposed approach utilizes the protocol-based generalized UKF and exhibits superior performance.

Probabilistic modeling of double linear damage accumulation and its application in fatigue reliability analysis

AbstractIn this paper, a probabilistic double linear damage accumulation model is proposed to characterize the uncertainty of damage accumulation using the statistics of material fatigue life. The probabilistic modeling framework is performed under normal distribution assumption of fatigue life. By applying a one‐to‐one probability density function transformation method, the probability distribution of critical damage and cumulative damage can be extracted and derived. The proposed probabilistic damage accumulation model is then used for fatigue reliability analysis by building the reliability formulas with respect to the cumulative damage and the critical damage under both constant and variable amplitude loadings. It treats the mean and variance of cumulative damage as time‐dependent values that dynamically vary with increase in usage life. The reliability can be easily calculated by limited data necessary from fatigue life samples. The applicability of the proposed method is demonstrated using the experimental data of two metallic materials under constant amplitude and two‐block loadings. The results show that the model predictions are in good agreement with the experimental observations under constant amplitude loading and L‐H loading sequence. In addition, the proposed method provides better predictive ability than the Miner rule under constant amplitude loading and H‐L loading sequence. Moreover, the predicted reliability plots can typically present a two‐stage fatigue characteristic during crack initiation and crack propagation periods.

Stabilization of constant power loads and dynamic current sharing in DC microgrid using robust control technique

DC microgrids are appealing in distribution networks due to their high efficacy, stability, and ease of incorporation with renewable energy resources. In order to maintain system reliability, load sharing is crucial, because disturbances such as the constant power load (CPL), constant voltage load (CVL), uncertainty parameters, and variations in input voltage may result in instability. The conventional droop control method has been frequently employed to regulate the DC microgrid. However, under significant disturbances, conventional droop control is not suitable for achieving both accurate current sharing and acceptable voltage regulation. To tackle these limitations, this paper introduces a robust control for sharing load current and regulating DC bus voltage in a DC microgrid feeding a CPL and CVL. The proposed approach is split into two loops. The main loop, which is based on an RST controller, is used to regulate the current load sharing between two parallel boost DC/DC converters, handle the instability issue caused by disturbances, and improve system reliability. The DC bus voltage is adjusted using the secondary loop built using the proportional-integral (PI) controller. The key benefits are precise voltage regulation, load power sharing, and good reliability. Aside from that, the RST controller has great resilience, quick dynamic response, and strong stability for significant load fluctuations. The feasibility and efficacy of the proposed approach are confirmed by time-domain simulation results, and hardware-in-the-loop (HIL) testing under various scenarios. The obtained findings show that the suggested control strategy is capable of ensuring proportionate power-sharing while dealing with DC voltage instability under CPL, CVL, uncertainty parameters, and input voltage fluctuations.

A study of surface fatigue wear and influence of contaminated lubricant in journal bearing system using tribological and vibration analyses

In the present work, journal bearing performance was evaluated using condition monitoring processes namely wear debris, vibration signal, lubricant oil degradation and temperature analyses. The journal bearing system was operated at 800 rpm and 200 N constant speed and load over a period of 1200 h. The lubricant oil samples were collected for every 300 h of test duration for oil degradation and wear particle analyses by using Fourier transform infrared radiation (FTIR) and scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDS) techniques, respectively. FTIR results provided specific chemical bonds and functional groups contained in the degraded oil. The vibration signals were acquired for every 100 h of operation, and a fast Fourier transform (FFT) frequency spectrum technique was employed for vibration signal analysis. The friction coefficient and specific wear rate parameters were considered to evaluate the tribological performance of the journal-bearing system. Statistical parameters, namely root-mean-square and kurtosis, were evaluated. Wear mechanisms such as abrasive, adhesive and surface fatigue wear were observed on the journal-bearing contact surfaces using a USB optical microscope. The scoring on the bearing element confirmed the fault development and resulted in an increase in vibration amplitudes. Higher mass loss in the bearing material was observed due to high friction and wear rates owing to its being a softer material than that of the journal material. The results obtained from the aforementioned parameter assessment techniques provided a reliable information on the defects which appeared on journal-bearing contact surfaces.

Fire resistance of square concrete columns reinforced with GFRP bars, experimental and numerical investigation

Glass Fiber Reinforced Polymer (GFRP) materials have proven its efficiency in reinforcing concrete elements. The performance of Glass reinforced concrete columns (GRC columns) under axial loads have been studied well experimentally and numerically, While there are a very limited studies about the behavior of reinforced concrete GRC columns when exposed to fire. The weak performance of GFRP bars under fire compared to steel gave a warning about ignoring the fire behavior of GRC columns in fields. The fire performance of square GRC columns has been investigated experimentally and numerically in this study. The experimental program was done by testing nine GRC columns under design fire curve. All columns were tested under constant load during fire. Fire temperature was controlled to follow the design fire curve. Different parameters were investigated in this research; applied load ratio, concrete cover, and column configurations on the fire performance of GRC columns. Fire resistance (FR) of all tested columns were recorded and some recommendations about the FR of GRC columns were developed. The numerical study was conducted using the nonlinear finite element software. 3D-model using ABAQUS program was calibrated to reach the best simulation of GRC columns exposed to design or standard fire curve. The numerical study was done to extend the investigation of the experimental program. The influence of the various parameters have been examined to govern the fire performance of GRC columns. The experimental and numerical studies revealed that the fire resistance of GRC columns is highly affected by the applied load during fire. The difference between FR of GRC columns compared to steel-RC columns (SRC columns) was significant at eccentricity to width ratio greater than or equal to 0.2 and at higher applied load ratios. Spalling has a significant influence on the fire resistance and modes of failure of GRC columns.

Air Equalizing Mechanism in Cooling Performance Improvement of Vertical Delta-Type Radiators

Based on the design and measured data of one actual tower, a three-dimensional numerical model for a natural draft dry cooling tower (NDDCT) was created and validated under constant heat load. This enabled the performance improvement mechanism of air equalizing on vertical delta-type radiators (VDRs) to be clarified by detailed analysis of key parameters, such as the exit water temperature, heat transfer coefficient, and mass airflow. Under the impact of typical ambient crosswind, all VDRs were retrofitted with air-side-equalizing devices. It was found that the exit water temperatures of the whole NDDCT decreased by 0.865 °C, 0.593 °C and 0.186 °C under the studied ambient crosswind speeds of 2.5 m/s, 4 m/s and 12 m/s, respectively. The performance improvement mechanism of air-side equalizing was investigated for three VDRs, which were located on the upwind, tower lateral, and downwind sides under crosswind impacts. Besides the studied VDRs, the performance of the neighboring VDRs behind them was also improved by the optimized aerodynamic field and the reduced hot wind recirculation around them. In addition, the average heat transfer coefficients of the VDRs were enhanced, which could lay the foundation for improving the cooling performance of thermodynamic devices with VDRs.

Seismic behavior of novel resilient and corrosion-resistant composite columns using strain-hardening engineered cementitious composites and steel-FRP composite bars

This paper proposed a novel composite column with exceptional resilience and corrosion resistance achieved through the casting of engineered cementitious composites (ECCs) in the plastic hinge region and the utilization of steel-FRP composite bars (SFCBs). A total of six specimens were tested under constant axial load and cyclic lateral load to examine their seismic performance and reparability. The influence of the type of longitudinal reinforcement (steel bar, SFCB, and GFRP bar) and the matrix type (ECC and concrete) in the plastic hinge region was discussed. Test results indicated that configuring SFCB in the columns facilitated drift-hardening characteristics, which in turn enhanced resilience. The adoption of ECC in the plastic hinge region further reduced residual deformation of the composite columns while significantly improving both lateral strength and ductility. The maximum repairable limit of the specimens increases by a factor of 1.36, 1.86, and 2.5, respectively, as the FRP content increases from 0% to 31.3%, 56.4%, and 100%. The specimens reinforced with SFCBs can be quickly restored to their intended use without repair, before reaching a 2% drift ratio. The slip effect of SFCBs has a substantial impact on increasing the lateral displacement of test columns, and this effect tends to increase with an increase in FRP content. A fiber model was developed for predicting the skeleton curves, and its accuracy was validated through comparisons between the predicted and test results.

Cycle Tests and Structure Repair of Bridge Pier Models

This research was conducted in anticipation of the risk of fatal damage to the structure due to the earthquake. In this study, experiments were carried out on the test object in the form of a bridge pillar model, which consisted of 2 test steps. The cyclic test is in the form of a pier bridge model and is continued in step 2 in the form of repairs with grouting and carbon wrapping materials as well as conducting another cyclic test to evaluate the performance of the repair materials used. This study uses the pier model, which consists of two test objects, namely a column with dimensions of 0.25x0.25x1.68 meters and a column cap of 1.20x0.55x0.36 meters. This test provides a constant axial load of 0.2 fc’.Ag and a cyclic lateral load. Phase 1 testing was carried out until the drift ratio was 3.5%. The achieved lateral peak strength is 8,606 tonf with a drift ratio of 2.20%. Lateral strength experienced a decrease in peak lateral strength of 86.93%. The damage is dominated by shear cracks which are characterized by the number of cracks with a diagonal pattern. Structural performance analysis was carried out according to ACI 374.1-05. The results of the theoretical analysis of the peak strength of the pier model were 15.2144 tonnes in the tensile direction, while the experimental ones were 8.606 in the pushing direction and -7.812 in the pulling direction.

Low stress creep response of PTFE sealants applied to PEM fuel cells

AbstractViscoelastic properties of polytetrafluoroethylene (PTFE) play a crucial role in forecasting its long‐term behavior in engineering applications. An attempt is made to explore the viscoelastic properties of PTFE sealants that are utilized in polymer electrolyte membrane fuel cell (PEMFC). It is to be noted that PTFE sealants are vulnerable to creep under constant loading at elevated temperatures. Moreover, the creep of sealants will lead to leakage of reactants from the cell, which affects the performance of PEMFC. PTFE is an excellent choice as a sealant material in low‐temperature polymer electrolyte membrane fuel cell (LT‐PEMFC), which operates in the temperature range of 60–80°C. PTFE can be prominently used as sealants in high‐temperature polymer electrolyte membrane fuel cell (HT‐PEMFC), as it possesses no significant change in its physical properties within the temperature range of −150 to 300°C along with the working conditions of HT‐PEMFC. In LT‐PEMFC, the sealants will typically be subjected to low stresses in the range of 1–5 MPa. In this article, the creep response of PTFE sealant material is extensively studied at various temperatures of 25 (room temperature), 35, 45, 55, and 65°C and at three stress levels of 2, 3, and 4 MPa. The time–temperature superposition principle is utilized to develop master curve at a reference temperature of 25°C, to forecast long‐term creep characteristics of PTFE sealants. Moreover, the master curve for creep compliance is developed for 4.5 h.

Analysis of perforated corrugated steel columns subjected to bilateral cyclic loading

This research unveils numerical analysis of corrugated-shaped steel columns (CSCs) with perforations during seismic events. Using ABAQUS software, 34 tests were examined under constant and bilateral cyclic loads. Varying parameters involved numbers and levels of perforations, corrugation geometries, and steel thickness. Findings exhibited a favorable performance of CSCs with six corrugated geometries as compared with ones with four corrugated geometries. The enhancement in load capacities and ductility were reported at 25–32% and 40%, respectively. CSCs were seen most vulnerable to experience load capacity deterioration when perforations were located in the lower quarter zone of height. The maximum corresponding decline exceeded 30% among tests having all corrugated geometry faces perforated. Local buckling failure in the lower quarter zone was dominant in most cases with severe deformation observed by the presence of perforations in such zone. Increasing the steel thickness of CSCs improved load capacities satisfactorily and shifted the local buckling to outward buckling, and controlling the failure patterns. This research emphasizes the need for perforations in such innovative cross-section steel columns to play as service conducing area and cost-effective factor. The research also provides applicable solutions to optimize the structural behavior of CSCs and maintain safer design during seismic incidents.

Study of stress corrosion cracking susceptibility of irradiated ferrite-martensitic stainless steel 07Kh12NMFB in supercritical water. Part 2. Development of corrosion crack identification technique and analysis of autoclave test results

The studies of stress corrosion cracking have been carried out for the stainless ferritic-martensitic steel with chromium content of 12% irradiated to a damage neutron dose of ~12 dpa. This steel was chosen as a candidate material for the internals of supercritical water-cooled reactors (SWCR).The first part of the paper was devoted to autoclave testing of specially designed disk specimens under constant load in a supercritical water environment (at 450°C and 250 atm pressure). In this part of the article the developed technique for corrosion cracks identification is presented and analysis of autoclave tests results is performed.As a result of the experiments performed, the threshold stress values below which stress corrosion cracking initiation doesn’t occur. The values of threshold stresses are determined for the studied steel irradiated at temperatures of 390 and 550°C. Possible mechanisms of stress corrosion cracking of the studied steel are analyzed and directions for further research are proposed.

Fatigue behavior of load-carrying cruciform fillet weld joints under variable amplitude load

The objective of the current work is to study the mean stress effect of variable amplitude (VA) loading on the fatigue strength of load-carrying fillet-welded joints (LCFWJs). Experimental fatigue tests were carried out on LCFWJs made of S700 high-strength steel, considering constant amplitude (CA) and VA loads. In the case of VA loads, a Gaussian load spectrum shape with both constant minimum and maximum stress levels was considered to study varying mean stress conditions. Numerical analyses were conducted to determine the effective stresses at the weld root. The fatigue behavior of LCFWJs was evaluated using the 4R method, which takes into account the local stress ratio (Rlocal, i), material ultimate strength (Rm), residual stress (σres), and weld toe radius (r). Lower fatigue strength was found for the VA tests with the constant maximum stress tests compared to the CA tests when using damage parameter of D = 1.00, while the VA tests with the constant minimum stress tests showed higher fatigue performance. Nonetheless, employing damage parameters of D = 0.2 and D = 0.5 for variable amplitude loads with and without fluctuating mean stress conditions, respectively, provided conservative assessments compared to the design standards. By employing the 4R method, the precision of the assessments could be significantly improved, and the CA and VA fatigue test results fit into a single scatter band with scatter index of Tσ = 1.06 with damage sum of D = 1.00.

Gadolinium Doped Ceria as Nickel–Free Fuel Electrode in High Temperature CO2‐Electrolysis

AbstractIn this work, the performance, electrochemical processes, and stability of GDC (Ce0.8Gd0.2O1.9) fuel electrode containing single cells (GDC/8YSZ/GDC/LSCF) were examined in CO2 electrolysis conditions. The current density and area specific resistance is determined for different operation conditions. The examined cells showed a higher performance compared to state‐of‐the‐art Ni−YSZ fuel electrode (Ni‐YSZ/8YSZ/GDC/LSCF) based single cells with a similar production route. Furthermore, the cells were examined by means of electrochemical impedance spectroscopy (EIS) and the recorded data were evaluated by the distribution of relaxation times (DRT) analysis. An equivalent circuit model (ECM) consisting of four time constants and a Gerischer impedance (LR−RQ1−RQ2−G−RQ4−RQ5) was established to gain further insight into the individual processes in the cells. For instance, the low–frequency process P5 referring to RQ5 is the rate‐determining step in CO2 electrolysis and is assigned to a surface reaction including the charge transfer and possibly the gas diffusion in the GDC fuel electrode. A long–term stability test was performed in CO2 electrolysis conditions at 900 °C with a constant current load of −0.5 A ⋅ cm−2 for up to 1200 h. A degradation rate of 62 mV ⋅ kh−1 was observed. By EIS analysis, a similar contribution of the ohmic and polarization resistances to the degradation was determined. The low–frequency process P5 and thus the surface reaction including the charge transfer in the GDC fuel electrode is contributing most to the increase in polarization resistance. After the long–term stability test, scanning electron microscopy (SEM) analysis was carried out and a coarsening of GDC particles in the fuel electrode was observed.

The Electrical Conductivity, EMI Absorption Shielding Performance, Curing Process, and Mechanical Properties of Rubber Composites.

Three types of composites were tested for electromagnetic interference (EMI) absorption shielding effectiveness, the curing process, and their physical-mechanical properties. For the first type of composites, nickel-zinc ferrite, manganese-zinc ferrite, and both fillers in their mutual combinations were incorporated into acrylonitrile-butadiene rubber. The overall content of the filler, or fillers, was kept at 200 phr. Then, carbon black or carbon fibers were incorporated into each rubber formulation at a constant loading of-25 phr, while the content of magnetic fillers was unchanged, at -200 phr. This work focused on the understanding of correlations between the electromagnetic shielding parameters and electrical conductivity of composites in relation to their EMI absorption shielding effectiveness. The absorption shielding abilities of materials were evaluated within a frequency bandwidth from 1 MHz to 6 GHz. This study revealed good correlation among permittivity, conductivity, and EMI absorption effectiveness. Although the absorption shielding efficiency of composites filled only with ferrites seems to be the highest, the absorption maxima of those composites reached over 6 GHz. The application of carbon-based fillers resulted in the higher electrical conductivity and higher permittivity of composites, which was reflected in their lower absorption shielding performance. However, the composites filled with ferrites and carbon-based fillers absorbed electromagnetic radiation within the desired frequency range. The presence of carbon-based fillers caused improvement in the tensile behavior of composites. This study also demonstrated that the higher the ratio of nickel-zinc ferrite in combined magnetic fillers, the better the absorption shielding efficiency.

A Model for Chemomechanical Coupling of Kinesin-3 Motor.

Kinesin-3 motor, which is in the monomeric and inactive form in solution, after cargo-induced dimerization can step on microtubules towards the plus end with a high velocity and a supperprocessivity, which is responsible for transporting the cargo in axons and dendrites. The kinesin-3 motor has a large initial landing rate to microtubules and spends the majority of its stepping cycle in a one-head-bound state. Under the load the kinesin-3 motor can dissociate more readily than the kinesin-1 motor. To understand the physical origin of the peculiar features for the kinesin-3 motor, a model is presented here for its chemomechanical coupling. Based on the model the dynamics of the motor under no load, under the ramping load and under the constant load is studied analytically. The theoretical results explain well the available experimental data under no load and under the ramping load. For comparison, the corresponding available experimental data for the kinesin-1 motor under the ramping load are also explained. The predicted results of the velocity, dissociation rate and run length versus the constant load for the kinesin-3 motor are provided. The study has strong implications for the chemomechanical coupling mechanism of the kinesin-3 dimer. The origin of the kinesin-3 dimer in the predominant one-head-bound state is due to the fact that the rate of ATP transition to ADP in the trailing head is much larger than that of ADP release from the MT-bound head. The study shows that the kinesin-3 ADP-head has an evidently longer interaction distance with microtubule than the kinesin-1 ADP-head, explaining why in the initial ADP state the kinesin-3 motor has the much larger landing rate than the kinesin-1 motor and why under the load the kinesin-3 motor can dissociate more readily than the kinesin-1 motor. The online version contains supplementary material available at 10.1007/s12195-024-00795-1.