Increase Of Service Time Research Articles

Influence of bolt creep induced pre-tightening force relaxation on dynamic response of the bolted joint system

The bolted joint is an important link that affects the accuracy maintenance of the heavy-duty machine tool. Due to bolts of the crossbeam are under a preload of several hundred kN for an extended period, the bolt gradually creeps and elongates as the machine tool's service time increases. This relaxation of the preload results in a degradation of the bolted stiffness, weakening the dynamic response of the bolted joint system. To reveal that the degradation law of crossbeam bolting performance of the heavy-duty machine tool induced by bolt creep, based on the Norton-Bailey(NB) model, a method for analyzing the creep of bolts with precision threads is proposed, and the influence of thread geometry and friction coefficient on the creep stress relaxation of bolts is studied. Considering the interface contact, an interface contact stiffness model is derived based on fractal theory. The dynamic equation of the bolted beam system is established using the Matrix27 stiffness matrix. The dynamic response of the bolted system, resulting from the degradation of interface stiffness due to bolt creep, is analyzed. The results show that the stress relaxation of bolt creep is not only related to creep parameters, but also related to the mate-thread interaction. The dynamic model with Matrix27 stiffness matrix is comparable to experiment in calculation accuracy and efficiency, which provides technical guidance for machine tool dynamics analysis and effectively solves the scientific problem of beam bolting performance degradation during the service of heavy-duty machine tools.

The effect of oxidation on tribology behavior of nickel-graphite coated stainless steel SS420

The main solution to the challenge of maintaining maximum sealing in the compressor section of each gas turbine is the use of abradable coatings. These coatings have a double duty, including (a) maintaining the lagging and (b) protecting the tips of the rotor blades. Choosing the type of abradable coating primarily depends on the service temperature of the coating. Nickel-graphite (Ni-G) coating is a good choice for use up to 480 °C and, or steel/sub-alloy rotor blades. In this research, the Ni-G coating was applied by the flame spraying method of Ni-G powder with a thickness of about 250 μm on an SS420 stainless steel substrate. The effect of the composition of the bonding layer was also investigated using two compositions, Ni-5Al and NiCrAlY. Obtaining the knowledge of applying Ni-G coating by flame spraying, identifying the structural and compositional characteristics of the coating (through optical and electron metallography), and the effect that oxidation can have on the tribological behavior of the coating were among the goals of this project. The best conditions for spraying the Ni-G coating were achieved an oxygen gas pressure of 6 bar, oxygen flow rate of 18 L min−1, acetylene pressure of 1.5 bar, acetylene flow rate of 24 L min−1, and the distance between the gun head and the sample surface was 22 cm. The results showed that placing the coating in oxidizing conditions increases its coefficient of friction. The increase in the coefficient of friction was attributed to the formation of oxide shells on the surface of the coating after 500 h of exposure to oxidation conditions. Corresponding to the higher coefficient of friction, the oxidized coating showed a decrease in wear resistance as a result of oxidation. This result can show the decrease in abradable of this coating with increasing service time.

Reliability analysis of thermal barrier coatings under CMAS deposition and penetration

To address the issue of thermal barrier coating (TBC) failure and spalling caused by the deposition and infiltration of environmental particulate matter, a thermal-mechanical coupling model for EB-PVD TBC considering CMAS deposition failure was developed. Based on this model, the effects of CMAS deposition thickness and infiltration depth on TBC spalling failure were numerically studied. First, the deposition characteristics of CMAS were obtained using a critical velocity model. Second, the corresponding TBC failure criteria were established. Then, the effects of CMAS deposition thickness and infiltration depth on TBC spalling failure were specifically studied under different CMAS particle sizes and service times. The results show that the CMAS deposition thickness is the greatest at the leading edge and the pressure surface near the trailing edge of the blade. The CMAS infiltration depth is influenced by the temperature field, with higher temperatures leading to greater infiltration depth. With the simultaneous increase of service time and particle size, the average damage value of the coating surface (D¯) initially increases slightly to 0.2, then rapidly to 0.9, and finally slowly to 0.97, resulting in almost complete failure and spalling of the coating.

Fragility Analysis of a Transmission Tower-Line System Subjected to Wind and Ice Loads Considering Fatigue Damage

Disasters such as ice and wind can pose a serious threat to the normal operation of power transmission lines. Wind-induced fatigue damage can further reduce the load-carrying capacity of transmission towers, increasing their fragility to ice and wind disasters. To assess the comprehensive capability of transmission towers to resist extreme ice and wind disasters, this paper proposes a failure probability evaluation framework for transmission towers considering wind-induced fatigue damage under the coupled effect of ice and wind. Taking a certain transmission line in Hunan as an example, the failure probability caused by ice and wind disasters is calculated for different years of service. First, based on the historical meteorological data in three cities in Hunan, a joint probability model of wind speed and wind direction considering their correlation is established using the copula function. Then, based on this probability model, the wind-induced fatigue damage of transmission towers is calculated using the Miner linear damage theory and the S-N curve. Subsequently, the fragility of the tower under the coupled load of ice and wind is calculated for different years of service. Finally, by combining the structural fragility function with the joint probability distribution model of ice thickness and wind speed, the collapse probability of the transmission tower under the action of ice and wind disasters is calculated. The results indicate that the influence of wind-induced fatigue damage cannot be ignored when transmission towers encounter ice and wind disasters. With increasing service time, the ability of transmission towers to resist ice and wind disasters gradually decreases, and the failure probability also increases under extreme ice and wind conditions.

Real-Time Quantitative Evaluation on the Longitudinal Slip Performance of Spherical Steel Bearings of Long-Span Bridges

Spherical steel bearings play an important role in the normal longitudinal expansion of the main girders of long-span bridges. With the increase in service time, the wear damage will deteriorate the longitudinal slip performance of spherical steel bearings. In this research, a method of real-time quantitative evaluation on longitudinal slip performance is proposed through monitoring data analysis, correlation analysis, damage evaluation analysis, and experiment data analysis. Monitoring data analysis shows that the temperature field has a good linear relationship with longitudinal displacement. Correlation analysis shows that this relationship is well described by a time-varying multiple linear regression model. Furthermore, bearing friction is used as an index for real-time quantitative evaluation, and a large value of bearing friction indicates serious damage. An evaluation model considering the influence of temperature field and bearing frictions is proposed. The time-varying values of bearing frictions are calculated through Kalman filtering analysis. Experimental results show that the maximum evaluation error of this method is less than 5%, verifying that the proposed method is feasible for real-time quantitative evaluation on the longitudinal slip performance of bridge bearings.

Ultrasonic Non-Destructive Testing on Fast-Charging Lithium-Ion Battery’s Capacity Fading

Fast charging technology provides a solution to the issue of charging time for power supplies with long life requirements. However, it will shorten the charging period while also hastening the power battery’s capacity degradation, reducing its service life. The ultrasonic inspection technique has been widely used for the internal structure detection and reaction process characterisation of lithium-ion batteries because of its nondestructive testing properties. This paper presents a method for monitoring the capacity attenuation of a fast-charging battery by calculating the ultrasonic attenuation coefficient α. The experimental findings indicate that the battery’s capacity is more vulnerable to lithium plating during high-rate charging. The parameter α can be employed to illustrate the energy dissipation characteristics of sound as it propagates through the electrode. Moreover, the inhomogeneous ageing of battery electrode material is observed and quantified based on the differences in acoustic signals, which provides new insights into battery health management and uneven ageing assessment.

Life-cycle seismic performance of Q690 steel columns with H-section under various bi-directional cyclic loading paths

The ageing effect in the life-cycle assessment should be considered for the high-strength steel structures constructed in corrosive environments and high-seismicity zones. Additionally, the structures can suffer multi-dimensional seismic excitations because of the spatial effect of ground motions. Therefore, this study aims to investigate the impact of different loading protocols on the mechanical properties of Q690 steel columns with H-section during the whole life-cycle. Firstly, numerical methods considering time-varying corrosion process are used to simulate the ageing steel columns. After that, the nonlinear hysteretic behaviors of the ageing steel columns under different loading protocols are investigated. The factor of resistance degradation (the degree of degradation of ultimate resistance) is employed to quantify the effect of loading protocols on ageing steel columns. Finally, the biaxial ultimate interaction curve considering the ageing effect and a practical design process are proposed. The findings demonstrate that the steel columns exhibit different mechanical properties under various loading protocols, and the coupling direction of bi-directional displacement loads influences the degree of degradation of ultimate resistance. As service time increases, the factor of resistance degradation of steel columns gradually reduces by up to 40%. The proposed biaxial ultimate interaction curve has acceptable accuracy. These findings emphasize the importance of employing the unfavorable loading protocols in conducting the seismic design of the steel columns in different life-cycle stages.

Time-variant seismic resilience of reinforced concrete buildings subjected to spatiotemporal random deterioration

Corrosion-induced deterioration weakens the seismic capacity of buildings in coastal areas. This paper presents an investigation into the seismic resilience of RC frame structures experiencing spatiotemporal random deterioration. Two probabilistic distributions of corrosion were simulated using two modeling approaches: uniform and spatial corrosion assumptions. The incremental dynamic analysis (IDA) approach was used to obtain fragility curves for a 5-story RC frame designed according to Chinese codes. The impact of corrosion over a service life ranging from 0 to 50 years was assessed. The loss evaluation was subsequently conducted using the method proposed by Federal Emergency Management Agency (FEMA). The functionality curves and normalized resilience indices for different seismic hazard levels were estimated. The results indicate that the seismic probabilistic capacity and resilience of the 5-story RC frame studied here decrease as service time increases. The damage to structural members is more sensitive than that to nonstructural components. The total losses of the RC frame investigated in this study mainly result from nonstructural repair losses at first, then the collapse losses will become the main contributor to total loss as the seismic hazard level increases. Both uniform and spatial corrosion modeling approaches are valuable for representing the impact of corrosion on the restoration capabilities of RC frames.

Study on the temperature rise characteristics of aging lithium-ion batteries under different cooling methods

Lithium-ion batteries have been widely used in electric vehicles and electrochemical energy storage power stations. With the increase of service time, the single cells in the battery module will age to varying degrees, resulting in inhomogeneous heat generation and even safety accidents. Considering that there is currently limited research on the cooling effect of battery cooling technology on aging batteries, this article adopts a new non-destructive method to study the uneven aging characteristics and the temperature rise characteristics under different cooling conditions of different cells in small aging lithium-ion battery modules. The results show that the irreversible heat generation power of cell 1, cell 2 and cell 3 during 1 C discharge is 1.23 W, 1.33 W and 1.15 W, respectively, showing different degrees of aging. However, the maximum temperature rise under natural heat dissipation conditions has the same change trend and the average temperature rise on the surface of three cells at the end of discharge is about 20 °C. The temperature rise at the edge of cell 2 and cell 1 with more serious aging is higher, while the temperature rise at the center of cell 3 with the smallest aging degree is higher. The temperature distribution at different positions on the surface of the three cells was slightly different. The maximum temperature difference at different positions on the surface of cell 2 (2.3 °C) was greater than that of cell 1 (1.5 °C) and cell 3 (1.6 °C). Then, a simple OCV test method and SEM characterization technique were used to analyze the aging characteristics of the electrode position corresponding to the external temperature monitoring position of cell 2, and the relationship between temperature distribution and aging characteristics was established. The cooling and uniform temperature ability of thermal pad, semiconductor cooling and liquid cooling plate/semiconductor composite cooling are improved in turn. Among them, the liquid cooling plate/semiconductor composite cooling is an efficient temperature control strategy which can make the temperature of cell 3 basically stable at 23 ° C during 1C discharge by reasonably regulating the cooling power, and the maximum surface temperature difference is maintained at 0.4 ° C. It is suggested that when the large cell is put into use, it should be equipped with an independent sub-regional precise temperature control system that can adjust the cooling power in real time according to the heat production rate of the battery, so as to improve the safety and promote the development of sustainable energy.

Horizontal bearing characteristic and seismic fragility analysis of CFRP composite pipe piles subject to chloride corrosion

This paper studies the time-dependent horizontal bearing characteristic and seismic fragility analysis of carbon fiber reinforced polymers (CFRP) composite pipe piles under chloride corrosion. A diffusion model of chloride ions in CFRP composite pipe piles is established based on Fick's second law, allowing for the prediction of corrosion initiation time of CFRP composite pipe piles. The flexural stiffness of composite pipe piles for different CFRP replacement ratios is calculated, and the time-dependent horizontal bearing capacity of CFRP composite pipe pile is calculated using the finite difference method. Considering the uncertainties of structural modeling and earthquake waves, an analysis is conducted to study the effect of earthquakes on piles with different CFRP replacement ratios at various service times. The seismic fragility curves are then derived. The research results show that with the increase of service time, the flexural stiffness of CFRP composite pipe piles decreases. Moreover, higher CFRP replacement ratios result in reduced loss of pile bending stiffness and greater stability of the flexural bearing capacity. As the service time increases, the failure probability of composite pipe piles under seismic action exhibits a smaller increase, particularly for higher CFRP replacement ratios, thereby resulting in a lower loss of seismic performance.

Time-varying traffic load model of expressway based on long-term monitored data from multiple regions — A case in central and eastern China

Traffic load is one of the main loads borne by highway transportation infrastructure, which seriously impacts the safe operation of the bridge and road. Due to the change in the external environment and government policy, the traffic load has obvious time-varying characteristics, which is the key to establishing the real traffic load model. The two main time-varying factors of traffic load are the growth of traffic volume and the evolution of vehicle weight. In the long-term research work, there is a lack of research based on continuous monitoring data for the above two factors. Therefore, this paper carries out a study on the time-varying traffic load model of expressways based on long-term monitored data from multiple regions. Firstly, the data sources of monitored 18 expressways in central and eastern China are introduced. Secondly, the Logistic model is selected as the basic model to study the growth laws of expressways from different provinces; meanwhile, the evolution of vehicle weight distribution is also analyzed and a simplified model is established accordingly. Finally, a case study of a newly opened eight-lane expressway is operated to characterize the influence of time-varying vehicles. The results show that the traffic volume and vehicle weight distribution change significantly with the increase of service time. The Logistic model and liner model are appropriate to characterize the evolution model of the traffic volume and vehicle weight distribution separately. The time-varying characteristics of traffic load have a significant impact on the standard fatigue traffic load model and the cumulative equivalent axle loads. The research results could provide a reference for the establishment of time-varying traffic load standard models for highways and the revision of related standards. At the same time, it could provide technical support for the full life-cycle investigation and design of the road and bridge infrastructure.

Analysis of wind time-varying performance of reinforced concrete electric pole under Marine atmospheric environment

Bearing capacity calculation model of concrete electric pole considering concrete long-term performance degradation and steel corrosion is established. The horizontal bearing capacity and wind resistance of typical concrete electric pole under Marine atmospheric environment are analyzed with service time. The effects of concrete protective layer thickness, stirrup diameter and strength coefficient on the long-term wind resistance of electric pole are discussed. It is found that with the increase of service time, the shear strength of the concrete pole deteriorates faster than that of the flexural strength, and the failure mode changes from bending failure to shear failure. The wind resistance of the pole after long service can be improved by increasing the thickness of the protective layer, adopting larger diameter stirrup and higher strength coefficient. The bearing capacity calculation model of concrete electric pole considering concrete long-term performance degradation and steel corrosion is established. The horizontal bearing capacity and wind resistance of typical concrete electric pole under Marine atmospheric environment are analyzed with service time. The effects of concrete protective layer thickness, stirrup diameter and strength coefficient on the long-term wind resistance of electric pole are discussed. It is found that with the increase of service time, the shear strength of the concrete pole deteriorates faster than that of the flexural strength, and the failure mode changes from bending failure to shear failure. The wind resistance of the pole after long service can be improved by increasing the thickness of the protective layer, adopting larger diameter stirrup and higher strength coefficient.

Life-cycle dynamic analysis and probabilistic seismic risk assessment of cross-fault hydraulic tunnels considering AAR-induced deterioration

The alkali-aggregate reaction (AAR) triggered the deterioration of the machinistic property of concrete materials is among the major negative factor that results in the reduction of structural serviceability and performance for concrete structures, especially for those hydraulic engineering in contact with water for service life-cycle. Hydraulic tunnels, being a vital component of hydraulic engineering, are frequently employed in various lifeline projects around the world. Once the AAR effect renders the hydraulic tunnel inoperable, the government and society will suffer enormous economic losses, delaying the achievement of carbon neutrality. However, current specification for seismic design does not account for the degradation of structural performance parameters induced by AAR effects, which cannot fully reveal the earthquake performance of AAR-affected tunnels during use. Having realized this challenge, this work presents a mechanical model of the AAR effect integrating the concrete elastic-plastic damage model to conduct the inelastic dynamic response and random earthquake risk assessment of AAR-affected cross-fault hydraulic tunnels with design life-cycle. To this end, a study of the AAR-affected hydraulic tunnels, which consider the fluid-structure-surrounding rock coupling systems throughout the service period, is undertaken to associate the structural reaction with the predefined evaluation index directly. Subsequently, The nonlinear dynamic assessment of cross-fault hydraulic tunnel is conducted by using increased dynamic method to generate several data. Besides, this research constructs the three-dimensional (3D) time-dependent fragility surfaces considering the AAR effect and seismic intensity level. The results of this study underscore this point that the AAR effect possesses the capability to aggravate the response of relative displacement and extend the cumulative damage cracking area of the cross-fault hydraulic tunnels (CFHTs) with the increase in service time. Similarly, the 3D time-varying fragility surfaces show that the longer the service time of AAR-affected cross-fault hydraulic tunnels, the more likely they are to collapse. The above phenomena demonstrate that the AAR effect can be recommended for the utilization in estimating the likelihood of the erosion of the building during service life-cycle and future seismic design code.

Residual Strength Modeling and Reliability Analysis of Wind Turbine Gear under Different Random Loadings

A novel method is proposed to investigate the pattern of variation in the residual strength and reliability of wind turbine gear. First, the interaction between loads and the effect of the loading sequence is considered based on the fatigue damage accumulation theory, and a residual strength degradation model with few parameters is established. Experimental data from two materials are used to verify the predictive performance of the proposed model. Secondly, the modeling and simulation of the wind turbine gear is conducted to analyze the types of fatigue failures and obtain their fatigue life curves. Due to the randomness of the load on the gear, the rain flow counting method and the Goodman method are employed. Thirdly, considering the seasonal variation of load, the decreasing trend of gear fatigue strength under multistage random load is calculated. Finally, the dynamic failure rate and reliability of gear fatigue failure under multistage random loads are analyzed. The results demonstrate that the randomness of residual strength increases with increasing service time. The seasonality of load causes fluctuations in the reliability of gear, providing a new idea for evaluating the reliability of the wind turbine gear.

Viscoelastic fracture mechanics-based fatigue life model in asphalt-filler composite system

Asphalt-based composites gradually reach the end of their life as the service time increases, which directly leads to fatigue failure of the pavement structure. However, there is currently a lack of a fatigue life model for asphalt-based composites that has a clear physical interpretation. To address this issue, a viscoelastic fracture mechanics-based (VEFM) fatigue life model is proposed to predict the fatigue failure life for asphalt-based composites in this study. The VEFM fatigue life model was established within a viscoelastic fracture mechanics framework and was applied to two types of asphalt-filler composite systems (AFCS). To obtain the model parameters and verify the proposed model, various tests including linear amplitude sweep tests, time sweep tests at low-stress levels and high-stress levels, as well as surface energy tests were conducted on AFCS. The results indicate that the established VEFM fatigue life model can be expressed as a function of the loading level, viscoelastic fracture parameters, initial shear modulus, and surface energy. The initial edge flow of AFCS increases with the temperature and has minimal effect on the fatigue life throughout the fatigue process. A critical fatigue failure point is defined by the curve of damage rate and damage density. The fatigue life of AFCS increases with the temperature while decreasing with the loading level.

A weakly supervised pairwise comparison learning approach for bearing health quantitative evaluation and remaining useful life prediction

PurposeThe purpose of this paper is to present a weakly supervised learning method to perform health evaluation and predict the remaining useful life (RUL) of rolling bearings.Design/methodology/approachBased on the principle that bearing health degrades with the increase of service time, a weak label qualitative pairing comparison dataset for bearing health is extracted from the original time series monitoring data of bearing. A bearing health indicator (HI) quantitative evaluation model is obtained by training the delicately designed neural network structure with bearing qualitative comparison data between different health statuses. The remaining useful life is then predicted using the bearing health evaluation model and the degradation tolerance threshold. To validate the feasibility, efficiency and superiority of the proposed method, comparison experiments are designed and carried out on a widely used bearing dataset.FindingsThe method achieves the transformation of bearing health from qualitative comparison to quantitative evaluation via a learning algorithm, which is promising in industrial equipment health evaluation and prediction.Originality/valueThe method achieves the transformation of bearing health from qualitative comparison to quantitative evaluation via a learning algorithm, which is promising in industrial equipment health evaluation and prediction.

High-temperature oxidation resistance of spent MoSi2 modified ZrB2–SiC–MoSi2 coatings prepared by spark plasma sintering

The spent MoSi2 modified ZrB2–SiC–MoSi2 coatings were prepared on carbon matrixes by spark plasma sintering. A continuous metallurgical bonding was formed at the interface between the coating and matrix, and no obvious defects such as pores and cracks were observed inside. The effects of spent MoSi2 content and trace doping in the spent powder on the oxidation behavior of the coatings in air at 1700 °C were investigated. During the active oxidation stage, the spent MoSi2 promoted the densification of the coating and enhanced the structural oxygen barrier properties. With the increase of service time, during the inert oxidation stage, doping an appropriate amount of spent MoSi2 helped to increase the fluidity of the rich-SiO2 protective layer so that the Zr oxides fully dispersed in the generated Zr–B–Si–O–Al multiphase glass layer, which could impede the penetration of oxygen and enhance the oxidation protection efficiency. However, excessive spent MoSi2 exacerbated the volatilization of gas by-products, forming pores and cracks in the glass layer and rising the oxidation loss. When the content of spent MoSi2 was 20 vol%, the glass layer is dense and uniform, with few defects and the best oxygen resistance property. Moreover, compared with commercial powders, spent MoSi2 contained Al2O3 and SiO2. Al2O3 had an excellent modification effect, while SiO2 glass can promote liquid phase sintering and seal the defects in the coatings. By adding spent MoSi2, the modified ZrB2–SiC–MoSi2 composite coatings could inhibit the formation of defects and improve the dynamic stability of the coatings effectively.

Analysis of the Creep Failure of P92/HR3C Dissimilar Steel Welded Joint

Harsh service environments, such as high temperature and pressure, cause many unforeseen premature failures, especially for welded joint structures, whose heat-affected zones have been in service. Cases of pressure vessel damage caused by premature cracking in the process often occur. In this paper, the finite element model of dissimilar welded joints of P92/HR3C steel was established to simulate the actual service process, and the variation law of maximum principal stress, equivalent stress, and stress triaxiality on the inner and outer surfaces of the joint and both sides of the welding were analyzed. The results show that in the long-term use of welded joints, the stress concentration occurs in the weld fusion zone; with the increase in service time, the creep strength of the HR3C weld interface is much higher than the P92 weld interface, the structural shape changes and the stress concentration is transferred from the HR3C-weld to the P92-weld.

Influence of Morphological Characteristics of Coarse Aggregates on Skid Resistance of Asphalt Pavement.

This research aims to improve the durability of skid resistance of asphalt pavement from the perspective of coarse aggregates based on on-site investigation. Firstly, the skid resistance of six representative actual roads was tested during two years by employing the Dynamic Friction Tester and the attenuation characteristics of skid resistance of different types of asphalt pavements were analyzed. Secondly, core samples were drilled onsite and coarse aggregates were extracted from the surface layer of the core samples. The morphological parameters of coarse aggregates were collected by a "backlighting photography" system and three-dimensional profilometer, and the variation rules of angularity and micro-texture of coarse aggregates were investigated. Finally, the correlation between the morphological characteristics of coarse aggregates and the pavement skid resistance was established based on the grey correlation entropy. The research results show that with the increase in service time, the attenuation rate of skid resistance of asphalt pavement gradually slows down; the angularity of coarse aggregates gradually decreases, and the micro-texture on the wearing surface gradually wears away. The grey correlation entropy between all the micro-texture indexes of coarse aggregates and dynamic friction coefficient, as well as between the roundness and skid resistance is more than 0.7, whereas the correlation between other evaluation indicators and the dynamic friction coefficient is poor, indicating that compared with the angularity of coarse aggregates, the micro-texture affects the skid resistance of actual asphalt pavement more greatly. In engineering applications, the use of coarse gradation, coarse aggregates with high roughness or high anti-wear performance can slow down the attenuation of pavement skid resistance, so that the pavement can maintain superior long-term anti-skidding performance.

An approach for simulating and evaluating the effect of sulfate attack on the durability of concrete bridges based on a three-dimensional cellular automata model

An accurate evaluation of sulfate attack (SA) diffusion and damage processes is critical for durability design in sulfate-contaminated environments. This study presents a three-dimensional cellular automata model algorithm (3D-CAm) that effectively simulates sulfate diffusion processes in concrete. The model's efficacy was verified through comparison with analytical solutions of Fick's second law (FSL), experimental data, and numerical methods reported in the literature. The outcomes demonstrate that the model has a high degree of accuracy in simulating the diffusion processes of SA in concrete. Moreover, based on the diffusion characteristics of sulfate, damage evolution, and deterioration of concrete mechanical properties, the 3D-CAm is developed and applied for modeling and evaluating the long-term effects of SA on the durability of a concrete bridge. The time and space-dependent multifactorial diffusivity stochastic effects were considered. The model algorithms are developed in Python to achieve this purpose. The simulation results revealed that the randomness of the multifactorial had a negative effect on the increasing sulfate diffusion and accelerating the degradation of the mechanical properties of concrete. Moreover, the relationship between sulfate concentration, damage degree, and corrosion time is presented. The results indicate that the damage degree plays a critical role in the deterioration of the mechanical properties of concrete, where with the increase in service time, the mechanical properties show a noteworthy decrease due to the increase in corrosion depth and deterioration of the cross-section area. To conclude, the 3D-CAm model provides a suitable and effective method for evaluating the diffusion and damage processes of SA in concrete bridges. It offers a valuable way to evaluate damage risk and design durable projects in corrosive environments.