Constant Stress Level Research Articles

Fatigue failure testing of human hair: Weibull-analysis for constant strain experiments

Fatigue failure testing of materials is an important aspect of assessing their strength and resilience under long-term, oscillatory stresses and/or strains. This also applies to human hair. For this investigation, we decided to complement existing experience on cyclic tests at various levels of constant stress with those at various constant strains (4–30%). For the description and analysis of the data sets, we opted for a non-linear fit of the cumulative two-parameter Weibull distribution (CWD) to the survival data. This gives direct access to the numerical values of the parameters as well as to their standard errors (SE), as measures of precision. As relevant parameters, we identified the lifetime index ln(α) and the shape factor β. All fits showed very high coefficients of determination and normally distributed residuals. Accordingly, precision of the parameter values is very high. It only starts to drop for high constant strains, when significant grouping of data starts to occur. ln(α) drops and β increases both exponentially with strain. β exceeds the value of unity (β ≥ 1) at a strain of 4.3%, indicating a fundamental change of failure mode. The cross-over of the theoretical curves for ln(α) and β occurs around 45% strain, which coincides with the break strain for conventional tensile testing. This agreement supports the validity of our approach and suggests a more than just empirical nature of the CWD-function for modelling the fatigue failure data of human hair.

Influence of Multiple Repair Welding on Microstructure and Properties of 06Cr19Ni10 Stainless Steel

AbstractRepair welding technology is widely used in the manufacturing and maintenance of rail transit equipment to repair welding defects. However, repair welding induces modifications in joint performance, and it is necessary to study the microstructure evolution behavior to reveal the reasons. In this study, the effects of multiple repair welding on the microstructure, mechanical, and fatigue properties of 06Cr19Ni10 stainless steel samples were studied. The surface texture and fracture morphology analyses of the samples were conducted by optical microscopy (OM), scanning electron microscopy (SEM), and its equipped backscattered electron diffraction (EBSD) technique. The mechanical and fatigue properties of the samples with different repair welding times were further obtained by hardness, tensile, and fatigue tests. The results show an increase in the grain size and the substructure content in the heat-affected zone (HAZ), and the austenite orientation is changed, attributable to multiple repair welding. Multiple heat inputs result in a significant increase in hardness from 165 HV to 185 HV, a noticeable decrease in tensile strength and elongation, and an upward trend in yield strength. Under the constant stress level, the heat input of multiple repair welding causes a decrease in the fatigue life and significantly reduces toughness in the instantaneous fracture zone of the secondary repair sample.

A microscopic approach to brittle creep and time-dependent fracturing of rocks based on stress corrosion model

A brittle creep and time-dependent fracturing process model of rock is established by incorporating the stress corrosion model into discrete element method to analyze the creep behavior and microcrack evolution in brittle rocks at a micro-scale level. Experimental validation of the model is performed, followed by numerical simulations to investigate the creep properties and microcrack evolution in rocks under single-stage loading, multistage loading, and confining pressure, at various constant stress levels. The results demonstrate that as the stress level increases in single-stage creep simulations, the time-to-failure progressively decreases. The growth of microcracks during uniaxial creep occurs in three stages, with tensile microcracks being predominant and the spatial distribution of microcracks becoming more dispersed at higher stress levels. In multi-stage loading-unloading simulations, microcracks continue to form during the unloading stage, indicating cumulative damage resulting from increased axial stress. Additionally, the creep behaviour of rocks under confining pressure is not solely determined by the magnitude of the confining pressure, but is also influenced by the magnitude of the axial stress. The findings contribute to a better understanding of rock deformation and failure processes under different loading conditions, and they can be valuable for applications in rock mechanics and rock engineering.

Creep compliance of functionalized graphene-epoxy nanocomposites

Creep behavior is observed even at room temperature in polymers and polymer composites under constant stress. In the design of structural elements using these materials, the determination of creep compliance for structural strength and performance analysis is crucial in terms of reliability and usability. In this study, the creep compliance of pure epoxy and functionalized graphene-reinforced epoxy nanocomposites were experimentally investigated and compared at room temperature at constant stress levels of 50, 100, and 200 MPa representing the viscoelastic region, yielding region and viscoplastic region, respectively. To reveal the effect of temperature as well as stress level on this behavior, the creep compliance of epoxy and graphene-epoxy nanocomposites was investigated at 65°C in addition to room temperature after the pure graphene used as a reinforcement element was functionalized with Triton X-100, nanocomposite production was carried out. In 2h creep tests, it was observed that as the constant stress level increased, the creep compliance increased and the creep compliance of the nanocomposite was lower than that of the epoxy at all stress levels. The creep compliance of the epoxy was improved by 65% with the addition of functionalized graphene at room temperature and a stress level of 100 MPa. As the temperature increased, the creep compliance of both epoxy and functionalized graphene-epoxy nanocomposite increased due to molecular mobility and viscous flow. However, at high temperatures, the positive effect of functionalized graphene on the compliance of the epoxy is higher. At 65°C and a stress level of 100 MPa, the improvement rate of creep compliance is 78%. Functionalized graphene exhibited a more effective behavior on creep resistance at high temperatures. The obtained results showed that creep compliance was significantly affected by stress level and temperature.

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.

Numerical Study of H2 Production and Thermal Stress for Solid Oxide Electrolysis Cells with Various Ribs/Channels

A fully coupled electro-thermo-mechanical CFD model is developed and applied to illuminate the crucial factors influencing the overall performance of a solid oxide electrolysis cell (SOEC), particularly the configuration and geometry parameters of its inter-connector (IC), comprising ribs and channels. Expanding on a selected width ratio of 4:3, the gradient ribs/channels are further investigated to assess electrochemical and thermo-mechanical performance. It is elucidated that, while maintaining constant maximum temperature and thermal stress levels, employing a non-regular geometry IC with gradient channels may yield a 30% enhancement in hydrogen production. These nuanced explorations illuminate the complex interplay between IC configuration, thermal stresses, and electrolysis efficiency within SOECs.

High-Cycle Fatigue Life Behaviour of Fabricated Glass Fibre-Reinforced Polymer

This study focuses on the fatigue behaviour analysis of glass fibre-reinforced polymer (GFRP) composite specimens under high-cycle fatigue loading conditions. Therefore, property validation is recommended in the material development process upon further investigation of the fabricated GRFP. This study aims to evaluate the behaviour of the fabricated GFRP fatigue specimen when subjected to high-cycle fatigue loads and compare it to existing studies. A GFRP fatigue test sample was fabricated using the hand layup process into a flat rectangular panel, which was then cut into a small dimension of 28×2×0.2 cm fatigue specimen. Fatigue tests were performed on five flat specimens at different constant amplitude loads or stress levels between 40% and 80% of ultimate tensile strength to obtain the stress–life curve for the fabricated GFRP. Results showed that the high-stress levels of 80% contributed to the most reduced fatigue life cycle of GFRP. This result is consistent with previous studies and lies within the published life cycle range, validating the fabricated GRFP. A new parameter called the failure modulus, or Mf, may be used to quantify a particular set of fatigue tests.

Durability assessment of GFRP bars exposed to combined accelerated aging in alkaline solution and a constant load

Employing fiber-reinforced polymer (FRP) bars as reinforcement in reinforced concrete (RC) elements is a promising approach to solve the issues associated with steel corrosion in RC elements owing to the high corrosion resistance of FRP bars. Although a number of studies on the durability of glass FRP (GFRP) bars in the alkaline environment are available, most of which ignored the influence of sustained loads. This paper presents an experimental program on tensile tests on GFRP bars made of three distinct matrix resins (i.e. epoxy, vinyl ester and polyester), after exposure to combined alkaline solution immersion, an elevated temperature and a constant load. A novel level device was developed, and a prescriptive constant axial stress was imposed on GFRP bars, and the bars with or without a sustained load were exposed to an alkaline solution and an elevated temperature of 60 °C. The main parameters investigated in the present study included aging times, constant stress levels, exposure conditions and types of resin matrices of the GFRP bars. The residual tensile properties of the GFRP bars were tested and presented. The microscopy method was adopted to check the internal defects in the GFRP bars with or without exposures. Test results show that three months of exposure in alkali and loading could lead to more than 40% strength decreases of the GFRP bars. Compared with GFRP bars after exposure to alkaline solution solely, the presence of the constant tensile load only leads to small further detrimental effect in tensile properties of GFRP bars.

Emergence of multiple set-points of cellular homeostatic tension

Stress fibers (SFs), a contractile actin bundle in nonmuscle mesenchymal cells, are known to intrinsically sustain a constant level of tension or tensional stress, a process called cellular tensional homeostasis. Malfunction in this homeostatic process has been implicated in many diseases such atherosclerosis, but its mechanisms remain incompletely understood. Interestingly, the homeostatic stress in individual SFs is altered upon recruitment of α-smooth muscle actin in particular cellular contexts to reinforce the preexisting SFs. While this transition of the set-point stress is somewhat a universal process observed across different cell types, no clear explanation has been provided as to why cells end up possessing different stable stresses. To address the underlying physics, here we describe that imposing a realistic assumption on the nature of SFs yields the presence of multiple set-points of the homeostatic stress, which transition among them depending on the magnitude of the cellular tension. We analytically derive non-dimensional parameters that characterize the extent of the transition and predict that SFs tend to acquire secondary stable stresses if they are subject to as large a change in stiffness as possible or to as immediate a transition as possible upon increasing the tension. This is a minimal and simple explanation, but given the frequent emergence of force-dependent transformation of various subcellular structures in addition to that of SFs, the theoretical concept presented here would offer an essential guide to addressing potential common mechanisms governing complicated cellular mechanobiological responses.

Creep and relaxation responses of fly ash concrete: Linear and nonlinear cases

The application of reinforced concrete has been used in various engineering and architecture fields. Stress relaxation and creep are two crucial time-dependent behaviours of concrete. The influence of two behaviours is closely related to the service life of the reinforced concrete structure. However, the research on experimental relaxation behaviour has rarely been extensively studied because of the complicated procedures. Meanwhile, fly ash is commonly utilised to partially replace cement to reduce the greenhouse effect. As a result, this study is committed to examining the creep and relaxation behaviour of fly ash concrete. The concrete creep and relaxation tests were designed to maintain a constant stress and strain levels, respectively. The creep and relaxation tests were conducted at the same time to minimise the shrinkage and ageing effects. The stress and strain levels were selected as 20% and 60% of concrete compressive strength to investigate creep and relaxation in linear and nonlinear cases. By comparing computed values of relaxation from the inverse of the compliance function, the estimated relaxation function showed good agreement using the inverse of the compliance function. However, the existing creep model showed a difference in predicting the creep of fly ash concrete. As a result, the existing model is amended to improve the estimation of creep and relaxation of fly ash concrete.

Simulation of the deformation diagram of a viscoelastic material based on a structural model

A serious problem in computer simulation of the stress state of polymer structures is to ensure the adequacy of the mathematical description of the mechanical properties of materials. The structural model of a viscoelastic material has a number of advantages in describing both the rheology of the material and trajectories of the material deformation. In this model, the material is described as a structure consisting of several elements with relatively simple rheological properties. Reproduction of a complex behavior of the material under alternating non-isothermal loading is ensured through the interaction of simple elements. A technique developed for modeling a viscoelastic material is intended for strength calculations of structures made of materials operating under conditions of prolonged repeated thermomechanical exposure using the finite element method. Application of the developed procedure to a polymeric material, polymethyl methacrylate (PMMA), is considered. The results of testing the material under uniaxial compression at a constant temperature are presented. The methodology and results of identification of the developed structural model using a specialized software are described. Formulas for approximation of the deformation characteristics of the material at a constant deformation rate and the time dependence of material deformation during the holding the material at a constant stress level are obtained. Approximation is an important step in identification of the material model which facilitates the systematization of the initial experimental data and their further mathematical processing. The best approximation of the deformation characteristics of a viscoelastic material is given by a hyperbolic tangent function, whereas the logarithmic function provides the best results for deformation upon exposure. Further construction of the structural model was carried out by selection of sequential parameters of bilinear rheological functions of the individual elements the model and iterative refinement of those parameters. The simulation results were compared with the experiments carried out at different strain rates and with exposure at different stress levels. We just present the results of the initial stage of the carried out experimental and theoretical studies.

Fine aggregate sizes effects on the creep behavior of asphalt mortar

Asphalt mortar consists of fine aggregates dispersed in an asphalt mastic (a matrix of asphalt binder and filler) and can have a significant influence on the high-temperature performance of asphalt mixtures. However, the fine aggregate sizes (FAS) governing the creep performance of asphalt mortar is not well understood. The effect of different FAS on the creep properties of asphalt mortar was investigated through experimental and numerical methods. A static compressive yield test and a dynamic triaxial creep test were performed on various asphalt mortar samples to determine their creep response under different conditions of temperature and stress level. It was found that the maximum strain in the asphalt mortar gradually reduces with an increase in FAS under the conditions of constant temperature – constant stress level, different temperature – constant stress level, and constant temperature – different stress level. Further, the modified Burgers model was proposed as a viscoelastic prediction model of asphalt mortar. A viscoelastic fitting analysis was carried out to validate the proposed model and the results indicated its adequacy for predicting the asphalt mortar’s creep response. At the end of the study, a grey relation entropy (GRE) analysis was done to quantify the degree of influence of the various FAS on the viscoelastic behavior of asphalt mortar. From the GRE analysis, FAS between 0.15 mm and 0.3 mm was found to be the most crucial. Below 0.15 mm FAS, asphalt mortar is mostly viscous. It begins to show elastic properties when the maximum FAS is between 0.15 mm and 0.3 mm, while above 0.3 mm and towards 2.36 mm the asphalt mortar increasingly becomes more elastic. The findings from this study can be useful to pavement engineers and other pertinent stakeholders seeking to optimize the aggregate gradation design of asphalt mixtures through the fine aggregate portion in order to enhance rutting resistance performance.

Generic creep behavior and creep modeling of an aged surface support liner under tension

Polymer-based materials have been motivated to be an alternative support system element in the mining/tunneling industry due to their logistic and geotechnical benefits. Thin spray-on liner (TSL), a term to define the application of the material on the rock surface with a layer ranging from 2 mm to 10 mm in thickness, shows some promising results. TSLs are mainly composed of plastic, polymer, or cement-based ingredients to a certain proportion. This study intends to reveal the time-dependent response of TSL specimens, cured throughout 500 d, under four constant stress levels for stable laboratory conditions. The results were correlated using two interrelated equations to predict the material's service life (creep-rupture envelopes). The proposed correlations offered an insight into both the effective permanent support time and the strain amount at the liner failure. The time-dependent deformation of TSL, whose performance is highly responsive to creep behavior, was obtained so that the design engineers may use the findings to avoid the severe problems of material creep. Experimental data were also used to develop a Burgers (four-element) creep model. Since the liner has a nonlinear time-dependent behavior, creep models were built for each stress level separately. Subsequently, a generic equation was obtained using the nonlinear parametric dependencies. There is a good agreement between the proposed model and the experimental results. The proposed model can be used as a basis for future numerical studies related to the support behavior of aged surface support liners.

RHEOLOGICAL CHARACTERISTIC OF VOLCANIC CLAY AND IMPLICATION TO ITS LONG-TERM STRENGTH AND TIME DEPENDENT BEHAVIOR

As a natural phenomenon, land movement does not occur suddenly, but it is a long-term phenomenon in the form of un-recoverable low rates deformation caused by constant stress on a slope body and known as creep. Therefore, it is very important to understand the rheological characteristics of the soil under constant stress and implication to its long-term strength and time dependent behavior of a soil mass. The laboratory shear creep tests were carried out on 15 undisturbed volcanic clay samples taken from the southern slopes of Lembang Village, Cililin, West Java, Indonesia. The tests were carried out by applying a constant shear stress level of 50% - 95% from the peak shear strength. The results show that the level of constant shear stress will affect to the rheological characteristics of the soil samples. The higher level of shear stress, the shorter failure time. Based on the shear creep tests, the rheological model was established, the failure time of the soil samples were estimated and the long-term strength equation was obtained. The long-term shear strength of the volcanic clay is decrease 52.38% from the peak shear strength and achieved after 925 days (±31 months). The cohesion (c) and internal friction angle (f) decrease from 41.548 kPa and 17.051o become 21.188 kPa and 9.129o, respectively. The shear creep test also shows that the soil shear strength parameters (c and f) are a function of time.

Hybrid thermal, mechanical and chemical surface post-treatments for improved fatigue behavior of laser powder bed fusion AlSi10Mg notched samples

Complex geometries can be produced by laser powder bed fusion (LPBF) techniques in a layer-by-layer manner. These parts exhibit inhomogeneous microstructure and poor surface quality in their as-built state. Performing post-treatments to modify these imperfections can play a substantial role in enhancing the performance of LPBF parts. However, the effects of post treatments on local geometrical irregularities are not still well documented. In this study, four different post-treatments including heat treatment, mechanical and chemical surface treatments as well as their combination were considered. Their effect was studied on microstructure, surface, and mechanical properties of LPBF V-notched AlSi10Mg samples. The as-built samples were subjected to two different shot peening processes (using different Almen intensity, shot diameter, and shot hardness), chemical polishing and electro-chemical polishing, in individual and combined configurations. Comprehensive microstructural characterization was carried out and the surface state of the samples was studied in detail in terms of surface morphology and roughness. In addition, mechanical properties including microhardness and residual stresses were measured and finally the fatigue behaviors of the samples were analyzed and compared at a constant stress level. All post treatments led to improved fatigue life. The combination of the aforementioned post-treatments led to a remarkable fatigue life improvement up to 414 times higher compared to the as-built state.

NOISE-INDUCED WORK STRESS DURING A TRAIN OPERATION

Train is a transportation that produces a high level of noise. Cabin crew as a person who work on the train will always be exposed to noise and have a greater chance to get work stress due to noise that will affect his work so that it can endanger passengers and the occurrence of train accidents. This study’s objective is to determine the impact of noise level toward work stress of cabin crew KA Kaligung Loco CC 201 DAOP IV Semarang. Noise level was measured using Noise Dosimeter and work stress was measured using DASS 21. The relationship between variables was analyzed using SPSS program with chi square method. Respondents were taken 30 cabin crew of KA Kaligung Loco CC 201 and as a comparison were taken 30 workers of Station Pocol as control variables. The result shown that there is a correlation between the increase in work stress level with noise (sig ,000). Based on noise sampling with case control methode for 3 days at KA Kaligung Loco CC 201 produces a noise value above the threshold 87 dBA during 4 hours 47 minutes that is 88 dBA, 93 dBA and 90 dBA. Station’s noise level as control is 74,78 dBA and this is result in under the threshold 85 dBA during 8 hours. While the average increase on cabin crew’s work stress reached 3,6 point. Whereas, Station Poncol’s workers have decrease work stress level until 3,3 point, From 30 cabin crew there were 26 respondents experienced an increase in work stress level, 3 respondents experienced a decrease in work stress level and 1 respondent had a constant stress level.

Creep behavior of full-culm Moso bamboo under long-term bending

Bamboo can be easily cultivated and harvested in a relatively short time and has been widely known as a sustainable building material. The study on the long-term creep behavior of full-culm bamboo members is of great significance for the design and use of bamboo structures in engineering, but there are few studies. This paper presents an experimental and numerical study on the creep behavior of full-culm original bamboo beams. In this study, two groups of bamboo beams with different stress levels were analyzed, and the fitting results based on Burger model were obtained. Short-term material properties test was firstly carried out to determine the ultimate strength of Phyllostachys edulis (or Moso bamboo). Secondly, in the creep test, 15 full-culm original bamboo beams were subjected to different constant stress levels for 180 days in an indoor environment, and the creep behavior of bamboo beams was observed and measured over time. Then a creep model of numerical analysis procedure based on the Burger model was established to simulate the creep behavior of each beam. By comparing the numerical analysis results with the test results, basic creep behavior characteristics including creep rate and proportion of each deformation (instantaneous elastic deformation, viscoelastic deformation and viscous deformation) were analyzed and discussed in depth. Finally, the creep behavior of full-culm original bamboo beams was evaluated by the acceptance criteria used for wood and wood-based products. The results indicated that the developed Burger model can well capture the trend of creep behavior including low and high stress level, and the full-culm original bamboo beam under lower stress level has the potential to replace timber in terms of withstanding long-term load. The creep test and numerical analysis of the full-culm original bamboo beams in this paper can provide a reference for follow-up study.

Quantitative thermography for fatigue damage assessment and life prediction of welded components

The objective of this paper is to use quantitative thermography for fatigue damage assessment and life prediction of welded components. The energy dissipation during fatigue process is taken as an effective index of fatigue damage to develop a nonlinear damage accumulation model, and the model is extended to evaluate the fatigue damage and residual life of the specimen subjected to variable loading. Experiments are performed to validate its applicability, and the relationships between the fatigue damage variable to the cycle number and the accumulated energy dissipation are presented and discussed. The results show that the energy dissipation has the same trend as the temperature increment evolution, and a power law relationship between the stress range and the energy dissipation is experimentally determined. The linear relationship between the accumulated energy dissipation and the cycle number is confirmed at different constant stress levels, and the total energy dissipation to failure is shown to be a constant value. The developed nonlinear damage accumulation model is used to predict the residual fatigue life, and a good agreement is achieved. It is concluded that the developed approach is applicable for fatigue damage accumulation and residual life evaluation of materials.

Numerical investigation on the effect of thickness and stress level on fatigue crack growth in notched specimens

The effect of specimen thickness on the behavior of fatigue crack growth rate (FCGR) requires rigorous investigation because the thickness effect is not independent and could be a function of the specimen geometry, material properties, loading conditions, and environmental conditions. The purpose of this study is to numerically investigate the effect of specimen thickness and stress level on the behavior of FCGR at the specimen-free surface and mid-thickness in notched mild steel specimens. Elastic-plastic numerical calculations were performed based on FEM using the domain integral method to calculate the cyclic J-integral parameter, ΔJ, which was used for calculating FCGR. Different specimen thicknesses and various constant amplitude stress levels were used in the numerical calculations. Crack growth calculations were carried out using the node release technique in which the history of the former crack was considered. The calculated fatigue lives were firstly verified against the experiments taken from the literature. The results of numerical calculations showed that no significant thickness effect was noticed at the mid-thickness for calculations carried out below general yield while when the stress level is close to general yield the thinner specimens showed faster crack growth rates. Further, thickness has a remarkable effect on the crack growth rate at the free surface when the applied stress level is below and close to general yield where the thinner specimens gave faster crack growth rates. The crack-tip driving force ΔJ and the local strains and stresses induced ahead of the crack front could explain the mechanics and behavior of FCGR for the applied thicknesses and stress levels. The distributions of the local strains and stresses could also reveal the effect of the local material ahead of the crack front on the behavior of crack growth.

A meso-mechanical approach to time-dependent deformation and fracturing of partially saturated sandstone

In the present paper, we investigate how water acts to weaken rock in two complementary ways: mechanically through the generalized effective stress principle, and chemically through time-dependent rock-fluid reactions that allow subcritical crack growth. These processes, together with capillary suction and stress corrosion , were incorporated into a three-dimensional discrete element grain-based model to investigate both the time-independent and the time-dependent mechanical behavior of partially saturated sandstone at the mesoscale . The capillary parameters related to capillary suction and subcritical parameters related to stress corrosion in the model were calibrated to match the deformation behavior of partially saturated sandstone observed in laboratory. Following this calibration, numerical simulations of partially saturated sandstone with different levels of saturation were performed in uniaxial compression. The simulations show that both the peak strength and elastic modulus of the sandstone decrease as a function of increasing saturation and that the relationships between these properties can be expressed by negative exponential functions. The simulations are in good agreement with the experimental results. Second, the long-term brittle deformation of partially saturated sandstone with different levels of saturation under a constant stress level was modeled. The results show that time-to-failure during brittle creep decreases, and the initial strain and the minimum creep strain rate increases, as a function of increasing saturation, as also observed in laboratory. The simulations also highlight the formation of tensile cracks as the main deformation mechanism during brittle creep. Finally, brittle creep in partially saturated sandstone samples with different levels of saturation was studied under different stress levels. These simulations show that the minimum creep strain rate and the time-to-failure as a function of stress can be well described by exponential relations. We conclude that the proposed model permits a deeper understanding of time-independent and time-dependent deformation and failure of partially saturated sandstone at the mesoscale.