Monotonic Uniaxial Compression Research Articles

Influence of Narrow Titanium Dental Implant Diameter on Fatigue Behavior: A Comparison between Unitary and Splinted Implants.

Background: Scientific literature lacks strong support for using narrow diameter implants (NDI) in high masticatory force areas, especially in molars. Implant splinting in cases of multiple missing teeth reduces lateral forces, improves force distribution, and minimizes stress on implants. However, no studies have evaluated the fatigue load resistance of unitary or splinted implants. Methods: This in vitro study compares five groups of new metal alloy implants, including unitary and splinted implants with varying diameters. Mechanical characterization was assessed using a BIONIX 370 testing machine (MTS, Minneapolis, MN, USA) according to ISO 14801. For each of the five study sample groups, (n = 5) specimens underwent monotonic uniaxial compression at break testing and (n = 15) cyclic loading to determine the maximum force (Fmax) and the fatigue life (LF) values. Scanning electron microscopy (SEM) was employed for the fractographic analysis of the fractured samples. Results: The Fmax values for unitary samples ranged from 196 N to 246 N, whereas the two-splinted samples displayed significantly higher values, ranging from 2439 N to 3796 N. Similarly, the LF values for unitary samples ranged from 118 N to 230 N, while the two-splinted samples exhibited notably higher values, ranging from 488 N to 759 N. Conclusions: The observed resistance difference between sample groups in terms of Fmax and LF may be due to variations in effective cross-sectional area, determined by implant diameter and number. Additionally, this disparity may indicate a potential stiffening effect resulting from the splinting process. These findings have significant implications for dental clinical practice, suggesting the potential use of splinted sets of small-sized NDI as replacements for posterior dentition (premolars and molars) in cases of alveolar bone ridge deficiencies.

Ultra-lightweight low-carbon LC3 cement composites: Uniaxial mechanical behaviour and constitutive models

The present study aims to characterize the constitutive models of a novel ultra-lightweight low-carbon LC3 cement composite (ULCC-LC3) under monotonic uniaxial compression and tension tests. The compressive stress–strain curves of ULCC-LC3 were obtained based on axial compressive tests. The curve characteristics were analyzed and the data was fitted with the existing concrete compression constitutive model. Modified axial compression constitutive model for ULCC-LC3 was proposed and verified using the independent test data and related data of ULCC in other literatures. The characteristics of tensile stress–strain curves of ULCC-LC3 were also analyzed and studied. Based on existing experimental data, the applicability of the Tetsushi et. al.’s model to this composite was verified. The experimental results show that use of PE fibers can improve the ductility of ULCC-LC3. As compared with normal concrete, ULCC-LC3 exhibits a higher compressive peak strain (over 0.3% for fiber reinforced specimens and over 0.5% for non-fiber reinforced specimens). These findings contribute to the understanding of the mechanical behavior of ULCC-LC3 and provide constitutive models that can be used in numerical simulations and engineering applications to promote the use of this novel ultra-lightweight low-carbon material.

Cyclic constitutive equations of rock with coupled damage induced by compaction and cracking

In this paper, the cyclic constitutive equations were proposed to describe the constitutive behavior of cyclic loading and unloading. Firstly, a coupled damage variable was derived, which contains two parts, i.e., the compaction-induced damage and the cracking-induced damage. The compaction-induced damage variable was derived from a nonlinear stress–strain relation of the initial compaction stage, and the cracking-induced damage variable was established based on the statistical damage theory. Secondly, based on the total damage variable, a damage constitutive equation was proposed to describe the constitutive relation of rock under the monotonic uniaxial compression conditions, whereafter, the application of this model is extended to cyclic loading and unloading conditions. To validate the proposed monotonic and cyclic constitutive equations, a series of mechanical tests for marble specimens were carried out, which contained the monotonic uniaxial compression (MUC) experiment, cyclic uniaxial compression experiments under the variable amplitude (CUC-VA) and constant amplitude (CUC-CA) conditions. The results show that the proposed total damage variable comprehensively reflects the damage evolution characteristic, i.e., the damage variable firstly decreases, then increases no matter under the conditions of MUC, CUC-VA or CUC-CA. Then a reasonable consistency is observed between the experimental and theoretical curves. The proposed cyclic constitutive equations can simulate the whole cyclic loading and unloading behaviors, such as the initial compaction, the strain hardening and the strain softening. Furthermore, the shapes of the theoretical curves are controlled by the modified coefficient, compaction sensitivity coefficient and two Weibull distributed parameters.

Experimental and numerical investigation of the uniaxial compression behavior of SRG-Jacketed R/C columns

This paper presents an experimental and numerical investigation of Reinforced Concrete (R/C) short columns strengthened with Steel Reinforced Grout (SRG) jackets. Nine specimens were constructed and tested under concentric monotonic uniaxial compression, measuring compressive force, axial and lateral displacements. Parameters of investigation were the influence of internal steel reinforcement (i.e. no reinforcement, sparse or dense stirrups) and the number of the externally applied SRG jackets (i.e. one or two layers). Subsequently, a three-dimensional finite element methodology was developed, aiming to predict the response of those specimens. Experimental results show that the strength and deformation capacity of the specimens was significantly enhanced with the addition of the SRG jackets, since the strengthening schemes provided sufficient passive confinement. The comparison between experimental and numerical results, in terms of failure mode, axial and lateral stress–strain curves, demonstrated satisfying correlation, proving the efficiency of the proposed numerical model.

Analysis of ductile damage and fracture under reverse loading

This paper investigates the influence of reverse and cyclic loading on the damage and fracture behavior of the aluminum alloy EN-AW 6082-T6. A series of uniaxial tension–compression and shear tests with newly designed shear specimen has been performed to analyze the development of plastic deformations and damage under different stress conditions. In addition, several monotonic uniaxial tension and compression tests are conducted to detect the strength-differential (SD) effect. Hence, combined hardening law is incorporated into the hydrostatic-stress-sensitive yield function to predict irreversible deformations under cyclic loading. A newly defined strain triaxiality is proposed to describe the strain state and to reveal the damage evolution processes. To accurately model cyclic plasticity, strain triaxiality is incorporated into the extended Voce strain hardening, and the angle parameter between effective back stress and reduced stress is added to Chaboche’s kinematic hardening. Furthermore, a modified anisotropic stress-state-dependent continuum damage model is considered to evaluate the damage and fracture evolution processes. Additionally, the digital image correlation (DIC) technique is applied to measure the strain fields during the experiment. Numerical simulations are used to predict the distribution of stresses and strains. Finally, the distribution and amount of damage are used to explain the fracture behavior detected by scanning electron microscopy (SEM) pictures taken in the critical parts of the specimens. SEM images and numerically predicted damage stains confirm that the different failure modes depend on the loading history.

Cracking Modes and AE Precursors of Sandstone Failure Under Multi-Stage Uniaxial Compression

Denudation processes induced by external loading show scale-independent traits in rocks. Therefore, monitoring of micro-cracking features offers a possibility for assessing the structural health or rock massifs; eventually leading to early-warning systems capable of estimating the risk of catastrophic collapses. This study assesses the behaviour of acoustic emissions monitored while a sandstone sample was subjected to staged monotonic uniaxial compression. Particularly, waveform characteristics were recorded and analysed to identify the most predominant factors for classification. Then an unsupervised k-means algorithm was employed to cluster these parameters into two categories, related to the source being either a tensile or shear dislocation. Clusters showed noticeable differences, whilst results indicate that properties of AE waveforms vary significantly amongst diverse stages of loading, being the rise time the most sensitive parameter. Moreover, it seems that transitions amongst diverse behavioural stages of the sample are preceded by changes in the first lag of the autocorrelation function and the variance of the ratio of maximum amplitude and rise time of the ensemble of time histories observed within each stage. This trend is significantly more noticeable during the last stage, just before the collapse. This trait is in accord with the critical slowdown theory (CSD). This allows for the development of early-warning systems signalling partial collapse of rock masses.

Experimental investigation of a spherical rubber isolator for use in low income countries

This paper presents an experimental study of a low-cost seismic isolator that can be used for the protection of low-rise houses in low-income countries. The isolator is based on rolling of a rubber sphere on flat or spherical concrete surfaces. Using a closely spaced grid of such spheres may allow for avoiding of the diaphragm slab at the isolation level, or of reducing its thickness. Avoiding the cost of this extra slab is crucial for building seismically isolated low-rise dwellings economically feasible in low-income regions of the globe.The effects of the geometry of the rolling surface (i.e., flat or concave), of the diameter of the rolling sphere (i.e., 25, 50 or 100 mm), and of the applied compressive load on the seismic behavior of such isolation bearings were investigated. Initially, the rubber isolators were subjected to monotonic uniaxial compression to examine their behavior under vertical loading. Subsequently, cyclic tests were performed to obtain the lateral force–displacement diagram of the isolation system. Finally, a slab supported by 4 isolators was subjected to a group of 61 ground motions. Eight different configurations were tested, leading to a total of 488 dynamic tests.It was found that the restoring force of such systems can originate not only from the curvature of the concrete surface, but also from the vertical motion induced by the drastic change of the shape of the rubber spheres, as well. In fact, for the configurations tested, the vertical motion sourcing from shape of the deformed sphere was much larger than the vertical motion sourcing from the curvature of the concrete surfaces.Moreover, equations offering the coefficient of friction as a function of the vertical load, the size and the deformation of the sphere were derived. This is crucial for design, as the governing parameter for the design of the rubber spheres is not material failure, but excessive compressive deformation that leads to undesirably high rolling friction. Dynamic tests proved that the proposed low-cost rolling rubber isolators can substantially reduce the accelerations transmitted to the superstructure The cost of the tested 25 mm, 50 mm and 100 mm diameter natural rubber spheres is 0.6 $, 3 $ and 17$, respectively.

Feasibility Study on Re-Using Tennis Balls as Seismic Isolation Bearings

This paper presents an experimental study of a low-cost seismic isolator that can be used for the protection of residential structures in low-income countries. The isolator is based on mortar-filled, used tennis spheres, rolling on flat or spherical concrete surfaces. The tennis spheres serve as permanent, spherical molds to cast mortar, and they are not removed after casting. The thin rubber shell of the tennis sphere offers increased damping and reduces stress concentrations at the contact areas. At the same time, this procedure creates a promising solution for the re-use of tennis spheres. Using a closely-spaced grid of such spheres may allow for avoiding the diaphragm slab at the isolation level, or reducing its thickness. Avoiding the cost of this additional, heavily reinforced isolation slab is crucial for making seismically isolated low-rise dwellings economically feasible in low-income regions of the globe. Initially, the tennis isolators were subjected to monotonic uniaxial compression to examine their behavior under vertical loading. Different mixes and low-cost reinforcement approaches to increase their strength were tested. Subsequently, cyclic tests were performed to obtain the lateral force-displacement diagram of the isolation system. The effects of the geometry of the rolling surface (i.e., flat or concave) and of the applied compressive load (i.e., 2.08, 3.23, 4.74, or 8 kN/sphere) on the cyclic behavior were investigated. It was found that the restoring force of such systems mainly originates from the curvature of the concrete surface. However, the vertical motion induced by the compressed sphere and its local casting imperfections is not negligible. When surface imperfections become significant, the force-displacement loops deviate from the bilinear curves that a rigid-body model suggests. When the spheres are properly cast, they experience zero damage even under 8 kN of compressive force, and their loops have a bilinear form. For the tested configurations, the rolling friction (defined as the ratio of lateral to vertical force at zero displacement) was in the range of 4.7–7.2%, thus suitable for seismic isolation applications. The cost of the tested tennis ball isolators was 0.05 $ per sphere.

Structural behaviour of pre-damaged RC columns immediate repaired employing pre-tensioned steel straps

Research focusing on the effects of pre-damaged level on the effectiveness of concrete repairing using external confinement is quite limited. In addition, the use of active confinement in concrete repair works is yet to be explored. This study extends the investigation on repairing reinforced concrete (RC) columns to the active-typed confinement. Experimental tests were conducted to investigate the applicability of active confinement in repairing RC columns with varied pre-damaged levels. The applicability of steel strapping confinement in repairing RC columns with the varied pre-damaged levels was confirmed through experimental works, which involved testing of 21 RC columns under monotonic uniaxial compression. The overall responses of the specimens were investigated in terms of crack pattern, load carrying capacity, axial displacement, stiffness and ductility of repaired columns. The test results have shown that the restorability of confinement was significantly affected by pre-damaged levels. It is also observed that the increase in confining volumetric ratio can restore both strength and ductility of repaired RC columns up to 171% and 172%, for the same pre-damaged level.

Fundamental Investigation on Seismic Retrofitting Method of Aging Concrete Structural Wall Using Carbon Fiber Sheet‐Constitutive Law of Rectangular Section

Aging building structure has become a world problem. This problem is particularly serious in developing and underdeveloped countries. The multihazard resilience and sustainability (e.g., seismic performance) decrease at the aging building. A construction method for strengthening aging‐reinforced concrete buildings by wrapping structural members with carbon fiber sheets has been proposed and implemented in recent years. Authors aim to develop a seismic retrofitting method of aging concrete structural wall with a rectangular cross section using carbon fiber sheets. In this paper, authors examined the stress‐strain relationship of concrete elements with rectangular cross sections reinforced by wrapping with carbon fiber sheets. Monotonic uniaxial compression tests were performed on 21 specimens using the ratio of the long side to the short side and the ratio of the element height to the short side of the concrete cross section, the weight of the carbon fiber sheet, and the chamfer radius of section corners as variables. The tests revealed that (1) the compressive strength decreases and ultimate strain increases as the ratio of the long to short side (longitudinal ratio) of the cross section increases even in a range the ratio exceeds 2 and (2) the ratio of the element height to the short side does not significantly affect the stress‐strain relationship. Furthermore, authors proposed evaluation formulas for the constitutive law of concrete elements with rectangular cross sections including the longitudinal ratio which exceeds 2 reinforced by carbon fiber sheets and confirmed that the formulas can reproduce the test results with good accuracy.

Determining stiffness modulus by means of different mechanical testing

Many research on mechanistic testing have come to likely conclusion that different test setup results in different performance. The aim of this paper is to analyse the stiffness modulus resulting from three different test setups, namely; Monotonic Uniaxial Tension Test (MUTT), Monotonic Uniaxial Compression Test (MUCT), and Indirect Tensile Test (ITT). They are monotonic tests. This paper will elaborate if there is any significant difference among the result of the first three tests. Master curves of stiffness modulus as a function of strain rate at reference temperature of 15°C were developed. The results show that there is no significance difference between the modulus resulting from the three tests performed at high strain rates. It’s also shown that at low strain rate, the elastic modulus resulting from compression tests is in between indirect and uniaxial tension test’s elastic modulus.

Strain and damage sensing of polymer bonded mock energetics via piezoresistivity from carbon nanotube networks

The strain and damage sensing abilities of randomly oriented multi-walled carbon nanotube (MWCNT) networks dispersed in the polymer binder of polymer bonded energetics are experimentally investigated. Monoclinic sugar crystals acting as mock energetics and aluminum powder acting as metallic fuel were added to simulate a fuel-oxidizer combination commonly used in the aerospace industry. MWCNTs were added to polydimethylsiloxane (PDMS), an elastomeric polymer binder, and hybrid mock energetics were fabricated. Four different material compositions were characterized based on the stress–strain response under monotonic uniaxial tension and compression to failure tests, allowing for the assessment of the effects of MWCNTs and aluminum powder on the average bulk elastic modulus, peak stress, and strain to failure. Along with mechanical loading, the piezoresistive response i.e. the change in resistance and reactance as a function of applied strain, was measured in both the elastic and failure regimes of the mechanical response for each material system. Gauge factors were calculated in three distinct regions of elastic behavior, microscale, and macroscale damage demonstrating the MWCNT network’s ability to sense strain, microscale damage, and macroscale fracture of mock energetic materials. Results observed herein demonstrate valid structural health monitoring applications for embedded carbon nanotube sensing networks in elastomer-based energetics experiencing significantly higher strain levels than prior proofs of concept with epoxy-based material systems.

Compressive behaviour of concrete columns confined with steel-reinforced grout jackets

Abstract This paper investigates the compressive strength of concrete columns confined with a new jacketing system using high strength steel reinforced fabrics embedded in an inorganic matrix (SRG). A comprehensive experimental programme was conducted on 52 cylindrical columns with SRG jackets and 15 control specimens under monotonic uniaxial compression load. The test specimens were designed to investigate the influence of different design parameters including the density of the fabric (1, 1.57, 4.72 cords/cm), number of layers (1, 2), overlap length (24, 36 cm), bonding agent (4 different types of mortar) and the concrete strength (16–30 MPa). The test results highlight the efficiency of the proposed method, where one-layered and two-layered SRG jackets could increase the strength capacity of the unconfined specimens by up to 122% and 193%, respectively.

Specimen aspect ratio and progressive field strain development of sandstone under uniaxial compression by three-dimensional digital image correlation

The complete stress–strain characteristics of sandstone specimens were investigated in a series of quasi-static monotonic uniaxial compression tests. Strain patterns development during pre- and post-peak behaviours in specimens with different aspect ratios was also examined. Peak stress, post-peak portion of stress–strain, brittleness, characteristics of progressive localisation and field strain patterns development were affected at different extents by specimen aspect ratio. Strain patterns of the rocks were obtained by applying three-dimensional (3D) digital image correlation (DIC) technique. Unlike conventional strain measurement using strain gauges attached to specimen, 3D DIC allowed not only measuring large strains, but more importantly, mapping the development of field strain throughout the compression test, i.e. in pre- and post-peak regimes. Field strain development in the surface of rock specimen suggests that strain starts localising progressively and develops at a lower rate in pre-peak regime. However, in post-peak regime, strains increase at different rates as local deformations take place at different extents in the vicinity and outside the localised zone. The extent of localised strains together with the rate of strain localisation is associated with the increase in rate of strength degradation. Strain localisation and local inelastic unloading outside the localised zone both feature post-peak regime.

Viscoelastic behaviour of hydrogel-based composites for tissue engineering under mechanical load

Along with biocompatibility, bioinductivity and appropriate biodegradation, mechanical properties are also of crucial importance for tissue engineering scaffolds. Hydrogels, such as gellan gum (GG), are usually soft materials, which may benefit from the incorporation of inorganic particles, e.g. bioactive glass, not only due to the acquired bioactivity, but also due to improved mechanical properties. They exhibit complex viscoelastic properties, which can be evaluated in various ways. In this work, to reliably evaluate the effect of the bioactive glass (BAG) addition on viscoelastic properties of the composite hydrogel, we employed and compared the three most commonly used techniques, analyzing their advantages and limitations: monotonic uniaxial unconfined compression, small amplitude oscillatory shear (SAOS) rheology and dynamic mechanical analysis (DMA). Creep and small amplitude dynamic strain-controlled tests in DMA are suggested as the best ways for the characterization of mechanical properties of hydrogel composites, whereas the SAOS rheology is more useful for studying the hydrogel’s processing kinetics, as it does not induce volumetric changes even at very high strains. Overall, the results confirmed a beneficial effect of BAG (nano)particles on the elastic modulus of the GG–BAG composite hydrogel. The Young’s modulus of 6.6 ± 0.8 kPa for the GG hydrogel increased by two orders of magnitude after the addition of 2 wt.% BAG particles (500–800 kPa).

Plastic deformation of high-purity a-titanium: model development and validation using the Taylor cylinder impact test

Results of an experimental study on the quasi-static and high-rate plastic deformation due to impact of a high-purity, polycrystalline, a-titanium material are presented. To quantify the plastic anisotropy and tension-compression asymmetry of the material, first monotonic uniaxial compression and tension tests were carried out at room temperature under quasi-static conditions. It was found that the material is transversely isotropic and displays strong strength differential effects. To characterize the material's strain rate sensitivity, Split Hopkinson Pressure Bar tests in tension and compression were also conducted. Taylor impact tests were performed for impact velocity of 196 m/s. Plastic deformation extended to 64% of the length of the deformed specimen, with little radial spreading. To model simultaneously the observed anisotropy, strain-rate sensitivity, and tension-compression asymmetry of the material, a three-dimensional constitutive model was developed. Key in the formulation is a macroscopic yield function [1] that incorporates the specificities of the plastic flow, namely the combined effects of anisotropy and tension-compression asymmetry. Comparison between model predictions and data show the capabilities of the model to describe with accuracy the plastic behavior of the a-Ti material for both quasi-static and dynamic loadings, in particular, a very good agreement was obtained between the simulated and experimental post-test Taylor specimen geometries.

Pre-Peak and Post-Peak Rock Strain Characteristics During Uniaxial Compression by 3D Digital Image Correlation

A non-contact optical method for strain measurement applying three-dimensional digital image correlation (3D DIC) in uniaxial compression is presented. A series of monotonic uniaxial compression tests under quasi-static loading conditions on Hawkesbury sandstone specimens were conducted. A prescribed constant lateral-strain rate to control the applied axial load in a closed-loop system allowed capturing the complete stress–strain behaviour of the rock, i.e. the pre-peak and post-peak stress–strain regimes. 3D DIC uses two digital cameras to acquire images of the undeformed and deformed shape of an object to perform image analysis and provides deformation and motion measurements. Observations showed that 3D DIC provides strains free from bedding error in contrast to strains from LVDT. Erroneous measurements due to the compliance of the compressive machine are also eliminated. Furthermore, by 3D DIC technique relatively large strains developed in the post-peak regime, in particular within localised zones, difficult to capture by bonded strain gauges, can be measured in a straight forward manner. Field of strains and eventual strain localisation in the rock surface were analysed by 3D DIC method, coupled with the respective stress levels in the rock. Field strain development in the rock samples, both in axial and shear strain domains suggested that strain localisation takes place progressively and develops at a lower rate in pre-peak regime. It is accelerated, otherwise, in post-peak regime associated with the increasing rate of strength degradation. The results show that a major failure plane, due to strain localisation, becomes noticeable only long after the peak stress took place. In addition, post-peak stress–strain behaviour was observed to be either in a form of localised strain in a shearing zone or inelastic unloading outside of the shearing zone.

Strengthening of RC columns by longitudinal CFRP sheets: Effect of strengthening technique

In the present study, the effect of utilizing longitudinal carbon fiber reinforced polymer (CFRP), as external compression reinforcement, on the behavior of strengthened RC columns is investigated. To do so, 10 RC columns including 5 circular columns with diameter of 150mm and 5 square columns with dimension of 133mm were cast. Four different methods including conventional externally bonded reinforcement (EBR) and near surface mounted (NSM) techniques, as well as the recently introduced grooving method (GM) in the forms of externally bonded reinforcement on grooves (EBROG, to be pronounced as /ebrΛg/) and externally bonded reinforcement in grooves (EBRIG, to be pronounced as /ebrIg/) techniques were used to strengthen the specimens in compression with CFRP. The specimens were tested under monotonic uniaxial compression, and different effects of the strengthening techniques were comprehensively discussed. Furthermore, an image-based deformation measurement technique, i.e. particle image velocimetry (PIV) was used to further investigate the stress transfer between longitudinal CFRP sheet and concrete substrate. Experimental results demonstrated that utilizing grooving method (GM) for bonding CFRP to concrete surface postpones the CFRP buckling, and subsequently, a significant increase in load carrying capacity of strengthened RC columns by compression CFRP sheets was observed.

Concrete columns confined with fibre reinforced cementitious mortars: Experimentation and modelling

The structural behaviour of concrete columns strengthened with a system made up of fibre nets embedded in an inorganic stabilized cementitious matrix under an uniaxial load was investigated. Medium size specimens with circular and square cross-section were cast and subjected to monotonic uniaxial compression, to investigate the efficiency of a p-Phenylene BenzobisOxazole (PBO) Fibre Reinforced Cementitious Mortar (FRCM) system in increasing both strength and ductility. The experimental results show that the confinement system adopted produced a noticeable increment in strength and ductility, though the low mechanical ratios of fibre considered were not always able to ensure hardening behaviour up to rupture. Modelling of concrete confined with FRCM is presented as a rather straightforward procedure through the sum of stress contributions of the confined concrete and the mortar of the confinement system, separately.

Micro-poromechanics model of fluid-saturated chemically active fibrous media.

We have developed a micromechanics based model for chemically active saturated fibrous media that incorporates fiber network microstructure, chemical potential driven fluid flow, and micro-poromechanics. The stress-strain relationship of the dry fibrous media is first obtained by considering the fiber behavior. The constitutive relationships applicable to saturated media are then derived in the poromechanics framework using Hill's volume averaging. The advantage of this approach is that the resultant continuum model accounts for the discrete nature of the individual fibers while retaining a form suitable for porous materials. As a result, the model is able to predict the influence of micro-scale phenomena, such as the fiber pre-strain caused by osmotic effects and evolution of fiber network structure with loading, on the overall behavior and in particular, on the poromechanics parameters. Additionally, the model can describe fluid-flow related rate-dependent behavior under confined and unconfined conditions and varying chemical environments. The significance of the approach is demonstrated by simulating unconfined drained monotonic uniaxial compression under different surrounding fluid bath molarity, and fluid-flow related creep and relaxation at different loading-levels and different surrounding fluid bath molarity. The model predictions conform to the experimental observations for saturated soft fibrous materials. The method can potentially be extended to other porous materials such as bone, clays, foams and concrete.