Increase In Maximum Stress Research Articles

Soft to tough: ordering in and tack of polymeric materials.

In the present paper, adhesive properties (in terms of practical work of adhesion, Wa, and maximum stress in probe tack test) of blends of polyvinyl pyrrolidone (PVP) with polyethylene glycol (PEG-400) are studied at different level of stretching stress, applied perpendicular to the probe. The anisotropic behavior in both directions is investigated. Upon stretching, blends of 50/50 wt% PVP-PEG demonstrate little decrease in tack and little increase in maximum debonding stress. Whereas for more cohesive blends like PVP-PEG mixtures with down to 35 wt% of PEG, a significant reduction in Wa at the size of an order of a magnitude is observed. Similar behavior is measured with a commercial product from 3M with the trade name "Command". For the first time, the anisotropy of probe tack properties of two identical strips after stretching is demonstrated via a specially designed quasi-2D setup, where the external force is applied either along or transverse the long side of the quasi-2D substrate, resulting in a significant difference in the measured probe tack curves. This phenomenon has been described by the block model, developed by Yamaguchi et al. We extended the block model by introducing the stretching stress into the model. The differences are explained by the difference in kinetics of the cavity growth between the two directions.

Innovative approach to determine the minimum wall thickness of flexible buried pipes

This paper uses a finite element based approach to provide a comprehensive understanding to the behaviour and the design performance of buried uPVC pipes with different diameters. It also investigates pipes with good and poor haunch support and proposes minimum safe wall thicknesses for these pipes. The results for pipes with good haunch support showed that the maximum pipe wall stress and deformation increase as the diameter increased. The results for pipes with poor haunch support showed an increase in the dependency of the developed vertical displacement on the haunch support as the diameter or the backfill height increased. Additionally, poor haunch support was found to increase the soil pressure, with the effect increasing as the diameter increased. The design of uPVC pipes for both poor and good haunch support was found to be governed by critical buckling. A key outcome is a new design chart for the minimum wall thickness, which enables the robust and economic design of buried uPVC pipes. Importantly, the methodology adopted in this study can also be applied to the design of flexible pipes manufactured from other materials, buried under different conditions and subjected to different loading arrangements.

Response of Velocity Anisotropy of Shale Under Isotropic and Anisotropic Stress Fields

We investigated the responses of P-wave velocity and associated anisotropy in terms of Thomsen’s parameters to isotropic and anisotropic stress fields on Longmaxi shales cored along different directions. An array of piezoelectric ceramic transducers allows us to measure P-wave velocities along numerous different propagation directions. Anisotropic parameters, including the P-wave velocity α along a symmetry axis, Thomsen’s parameters e and δ, and the orientation of the symmetry axis, could then be extracted by fitting Thomsen’s weak anisotropy model to the experimental data. The results indicate that Longmaxi shale displays weakly intrinsic velocity anisotropy with Thomsen’s parameters e and δ being approximately 0.05 and 0.15, respectively. The isotropic stress field has only a slight effect on velocity and associated anisotropy in terms of Thomsen’s parameters. In contrast, both the magnitude and orientation of the anisotropic stress field with respect to the shale fabric are important in controlling the evolution of velocity and associated anisotropy in a changing stress field. For shale with bedding-parallel loading, velocity anisotropy is enhanced because velocities with smaller angles relative to the maximum stress increase significantly during the entire loading process, whereas those with larger angles increase slightly before the yield stress and afterwards decrease with the increasing differential stress. For shale with bedding-normal loading, anisotropy reversal is observed, and the anisotropy is progressively modified by the applied differential stress. Before reaching the yield stress, velocities with smaller angles relative to the maximum stress increase more significantly and even exceed the level of those with larger angles. After reaching the yield stress, velocities with larger angles decrease more significantly. Microstructural features such as the closure and generation of microcracks can explain the modification of the velocity anisotropy due to the applied stress anisotropy.

Composite poly(ethylene carbonate) electrolytes with electrospun silica nanofibers

We prepared a ternary composite polymer electrolyte from poly(ethylene carbonate) (PEC), lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) and non‐calcined silica nanofibers (SNFs) having 3 average diameters (300, 700, and 1000 nm). The SNF composite electrolytes were obtained as homogeneous, self‐standing membranes. The ionic conductivity of PEC/LiTFSI 100 mol% was increased by the addition of SNFs, and the thinner SNFs with average diameter 300 nm were most effective in improving the conductivity. The conductivity was of the order of 10−4 S/cm at 60°C. The lithium transference number of the SNF300 composite was greater than 0.7. Stress‐strain curves of the composites indicated significant increases in Young's modulus and maximum stress for the PEC electrolytes. The 5% weight‐loss temperature of the composites also improved with the addition of SNF.

Studies on laws of stress-magnetization based on magnetic memory testing technique

Metal magnetic memory (MMM) testing technique is a novel testing method which can early test stress concentration status of ferromagnetic components. Under the different maximum tensile stress, the relationship between the leakage magnetic field of at certain point of cold rolled steel specimen and the tensile stress was measured during the process of loading and unloading by repeated. It shows that when the maximum tensile stress is less than 610MPa, the relationship between the magnetic induction intensity and the stress is linear; When the maximum tensile stress increase from 610MPa to 653MPa of yield point, the relationship between the magnetic induction intensity and the tensile becomes bending line. The location of the extreme point of the bending line will move rapidly from the position of smaller stress to the larger stress position, and the variation of magnetic induction intensity increases rapidly. When the maximum tensile stress is greater than the 653MPa of yield point, the variation of the magnetic induction intensity remains large, and the position of the extreme point moves very little. In theoretical aspects, tensile stress is to be divided into ordered stress and disordered stress. In the stage of elastic stress, a microscopic model of the order stress magnetization is established, and the conclusions are in good agreement with the experimental data. In the plastic deformation stage, a microscopic model of disordered stress magnetization is established, and the conclusions are in good agreement with the experimental data, too. The research results can provide reference for the accurate quantitative detection and evaluation of metal magnetic memory testing technology.

Biomechanical properties and cellular biocompatibility of 3D printed tracheal graft.

The goals of our study were to evaluate the biomechanical properties and cellular biocompatibility of 3D printed tracheal graft fabricated by polycaprolactone (PCL). Compared with native tracheal patch, there was a significant increase in maximum stress and elastic modulus for 3DP tracheal graft (p < 0.05). BMSCs were co-cultured under four different conditions to investigate cytotoxicity of the graft: (1) co-cultured with normal culture medium, as blank control; (2) co-cultured with perfluoropropylene, as negative control; (3) co-cultured with 3DP tracheal graft; and (4) co-cultured with polyvinyl chloride, as positive control. Moreover, the results of SRB assay showed that compared with blank and negative control group, there was no significant difference in the cell proliferation of 3DP tracheal graft group for 21days (p > 0.05). These results revealed that 3DP tracheal graft in our study has favorable cellular biocompatibility and biomechanical properties, and, therefore, will be a promising alternative for tissue-engineered trachea.

Evaluation of the thermal, mechanical and dynamic mechanical characteristics of modified graphite nanoplatelets and graphene oxide high-density polyethylene composites

Abstract The effectiveness of graphitic nanoplatelets (GNPs) and graphene oxide (GO) as reinforcing fillers in a high-density polyethylene (HDPE) matrix was evaluated based on morphological, tensile, dynamic mechanical, and thermal property improvements over the neat polymer. Simple melt compounding and injection moulding were used for sample fabrication. Filler loadings ranged from 0.1% to 10% for GNP, and 0.05%–1.5% for GO. Improvements in mechanical properties were observed in both composites for all investigated filler loadings, though more pronounced in the GNP composites, which saw a 56% increase in elastic modulus and 23% increase in maximum stress over neat HDPE for the 10% GNP composite. A slight increase in crystallization temperature was observed for the GNP composites, while a similar drop in melting point was recorded for both systems. SEM imaging revealed that agglomeration was present in both composites, though dispersion was better for the GNP/HDPE composites.

A viscoplastic response of a dual phase steel exposed to prior cyclic loadings

This paper presents an analysis of the influence of microstructural evolution due to fatigue loadings on the tensile behavior of a DP 500 dual phase steel. Firstly, the material was exposed to cyclic loadings at a number of cycles less than fatigue life. Subsequently, tensile characteristics of pre-fatigued specimens were determined at a wide range of strain rates. A testing machine and Kolsky bar were employed under quasi-static and dynamic deformation regimes, respectively. The results were used to develop a new constitutive model, based on a previous relation introduced by authors to describe mechanical behavior of pre-fatigued materials under quasi-static loading conditions. Original equation was modified by a new damage parameter, modification of the term corresponding to damage development and the addition of the strain rate sensitivity term. The new constitutive model takes into account the number of fatigue cycles and the maximum stress amplitude. Good agreement between experimental data and model predictions was obtained under both quasi-static and dynamic loading conditions. It was also found that lower cyclic stress (400 MPa) has no influence on the strain rate sensitivity. Higher cyclic stresses (450 MPa and 500 MPa) induce decrease of the rate sensitivity decreases with an increase of maximum pre-fatigue stress.

Cyclic compression response of micropillars extracted from textured nanocrystalline NiTi thin-walled tubes

Compression-compression cyclic deformation of nanocrystalline NiTi tubes intended for medical stents and with an outer diameter of 1 mm and wall thickness of 70 μm was studied using micropillars produced by FIB with the loading axis orthogonal to the tube axis. These micropillars were cycled in a displacement-controlled mode using a nanoindenter equipped with a flat punch to strain levels of 4, 6 and 8% in each cycle and specimens were subjected to several hundred cycles. The cyclic response of two NiTi tubes, one with Af of 17 °C and the other with an Af of −5 °C is compared. The texture of the tube with the Af of −5 °C was measured at the microscopic level using transmission electron microscopy and at the macroscopic level by X-ray diffraction and good agreement was noted. Characteristics such as i) a reduction in the forward transformation stress, ii) increase in maximum stress for a given displacement amplitude, and iii) a reduction in the hysteresis loop area, all with increasing number of cycles, observed typically during cyclic deformation of conventional macroscopic specimens, were captured in the micropillar cyclic tests. These observations lead to the conclusion that micropillar compression testing in a cyclic mode can enable characterizing the orientation-dependent response in such small dimension components that see complex loading in service, and additionally provide an opportunity for calibrating constitutive equations in micromechanical models.

Influence of geometrical and installation parameters on performance of CFRP anchors

This paper presents an experimental study of the geometrical and installation parameters affecting the maximum strength, failure mode and load-slip response of FRP anchors. In this study, single-shear tests were conducted on isolated carbon fibre ropes embedded in concrete to identify the variables that have a greater influence on the capacity of FRP anchors. Special attention was paid to variables influencing the stress concentration in the bending region. The parameters under evaluation included fabrication and installation method, embedment length, smoothing of the hole edge, hole diameter and dowel angle. The results demonstrate that increasing the embedment length leads to a proportional increase of maximum stress. Dowel angle and smoothing techniques can be combined to improve the anchor’s performance, as it was observed that both parameters reduce stress concentration and therefore enable higher bend strength.

Allowable stresses in high-frequency mechanical impact (HFMI)-treated joints subjected to variable amplitude loading

The effectiveness of high-frequency mechanical impact (HFMI) is considered to rely on the existence of compressive residual stresses. To determine when residual stress relaxation occurs, and what the resulting influence on fatigue improvement is, local stress-strain response in as-welded and HFMI-treated weld toes was modelled under different peak stress conditions. Then, effective notch stress analysis was used to correlate these results with available experimental observations. The simulations showed that high stress ratios and compressive peak stresses were critical with respect to residual stress relaxation, as expected. A compressive peak stress of 0.6f y (nominal yield strength) resulted in full residual stress relaxation. The relative fatigue damage calculations and the notch stress analysis indicated, however, that fatigue improvement could be expected even after significant residual stress relaxation. Based on this and previously observed benefit for high stress ratios, an increase in maximum allowable stresses for HFMI-treated welded steel joints is suggested. The maximum stress ratio is proposed to be increased from R = 0.52 to R = 0.7, and the maximum stress range to limit compressive stresses is proposed to be increased from ΔS max = 0.9f y to ΔS max = 1.2f y , which corresponds to S min = −0.6f y for stress ratio R = −1.

Quenching residual stress distributions in aluminum alloy plates with different dimensions

Finite element method (FEM) simulations were employed to investigate the quenching residual stress distributions of 7085 aluminum alloy plates. The effect of dimensional variation on the quenching residual stress distributions was studied and discussed by using models with different dimensions (length, width, and thickness). The accuracy and efficiency of the models were verified by other numerical examples. The order of the dimension effects on the quenching residual stress distributions is: thickness > width = length. The maximum tensile stress and compressive stress increase from 33 to 190 and 39 to 270 MPa, respectively, as the thickness increases from 30 to 150 mm. The ultimate maximum tensile stress (about 190 MPa) is equivalent to half of the quenching yield strength at 20 °C, while the ultimate maximum compressive stress (about 300 MPa) is equivalent to 80 % of the quenching yield strength at 20 °C. There are stress fluctuations at the edge of the large plate both in rolling and in transverse directions. The ratio of the fluctuation region along the rolling direction and transverse direction increases as the thickness increases, while it decreases as the length or width increases. The actual length of the fluctuation region is almost a constant value for the plates with a thickness of 115 mm (about 500 mm in length and 300 mm in width).

The Role of Fluid Dynamics in Distributing Ankle Stresses in Anatomic and Injured States.

In 1976, Ramsey and Hamilton published a landmark cadaveric study demonstrating a dramatic 42% decrease in tibiotalar contact area with only 1 mm of lateral talar shift. An increase in maximum principal stress of at least 72% is predicted based on these findings though the delayed development of arthritis in minimally misaligned ankles does not appear to be commensurate with the results found in dry cadaveric models. We hypothesized that synovial fluid could be a previously unrecognized factor that contributes significantly to stress distribution in the tibiotalar joint in anatomic and injured states. As it is not possible to directly measure contact stresses with and without fluid in a cadaveric model, finite element analysis (FEA) was employed for this study. FEA is a modeling technique used to calculate stresses in complex geometric structures by dividing them into small, simple components called elements. Four test configurations were investigated using a finite element model (FEM): baseline ankle alignment, 1 mm laterally translated talus and fibula, and the previous 2 bone orientations with fluid added. The FEM selected for this study was the Global Human Body Models Consortium-owned GHBMC model, M50 version 4.2, a model of an average-sized male (distributed by Elemance, LLC, Winston-Salem, NC). The ankle was loaded at the proximal tibia with a distributed load equal to the GHBMC body weight, and the maximum principal stress was computed. All numerical simulations were stable and completed with no errors. In the baseline anatomic configuration, the addition of fluid between the tibia, fibula, and talus reduced the maximum principal stress computed in the distal tibia at maximum load from 31.3 N/mm2 to 11.5 N/mm2. Following 1 mm lateral translation of the talus and fibula, there was a modest 30% increase in the maximum stress in fluid cases. Qualitatively, translation created less high stress locations on the tibial plafond when fluid was incorporated into the model. The findings in this study demonstrate a meaningful role for synovial fluid in distributing stresses within the ankle that has not been considered in historical dry cadaveric studies. The increase in maximum stress predicted by simulation of an ankle with fluid was less than half that projected by cadaveric data, indicating a protective effect of fluid in the injured state. The trends demonstrated by these simulations suggest that bony alignment and fluid in the ankle joint change loading patterns on the tibia and should be accounted for in future experiments. Synovial fluid may play a protective role in ankle injuries, thus delaying the onset of arthritis. Reactive joint effusions may also function to additionally redistribute stresses with higher volumes of viscous fluid.

A patient-specific virtual stenotic model of the coronary artery to analyze the relationship between fractional flow reserve and wall shear stress

ObjectiveAs the stenotic severity of a patient increases, fractional flow reserve (FFR) decreases, whereas the maximum wall shear stress (WSSmax) increases. However, the way in which these values can change according to stenotic severity has not previously been investigated. The aim of this study is to devise a virtual stenosis model to investigate variations in the coronary hemodynamic parameters of patients according to stenotic severity. MethodsTo simulate coronary hemodynamics, a three-dimensional (3D) coronary artery model of computational fluid dynamics is coupled with a lumped parameter model of the coronary micro-vasculature and venous system. ResultsTo validate the present method, we first simulated 13 patient-specific models of the coronary arteries and compared the results with those obtained clinically. Then, virtually narrowed coronary arterial models derived from the patient-specific cases were simulated to obtain the WSSmax and FFR values. The variations in FFR and WSSmax against the percentage of diameter stenosis in clinical cases were reproducible by the virtual stenosis models. We also found that the simulated FFR values were linearly correlated with the WSSmax values, but the linear slope varied by patient. ConclusionWe implemented 130 additional virtual models of stenosed coronary arteries based on data from 13 patients and obtained statistically meaningful results that were identical to the large-scale clinical studies. And the slope of the correlation line between FFR and WSSmax may help clinicians to design treatment plans for patients.

Fluid Dynamics Play a Role In Distributing Ankle Stresses in Anatomic and Injured States

Category: Basic Sciences/Biologics Introduction/Purpose: In 1976, Ramsey and Hamilton published a landmark cadaveric study demonstrating a dramatic 42% decrease in tibiotalar contact area with only 1 mm of lateral talar shift. An increase in principal stress of at least 72% is predicted based on these findings though the delayed development of arthritis in minimally misaligned ankles does not appear to be commensurate with the results found in dry cadaveric models. We hypothesize that synovial fluid is a previously unrecognized factor that contributes significantly to stress distribution in the tibiotalar joint in anatomic and injured states. Methods: As it is not possible to directly measure contact stresses with and without fluid in a cadaveric model, finite element analysis (FEA) was employed for this study. FEA is a modeling technique used to calculate stresses in complex geometric structures by dividing them into small, simple components called elements. Four test groups were investigated utilizing a finite element model (FEM): baseline ankle alignment, 1 mm laterally translated talus and fibula, and the previous two bone orientations with fluid added. The FEM selected for this study was the Global Human Body Models Consortium (GHBMC) M50 version 4.2, a validated model of an average sized male. The ankle was loaded at the proximal tibia with a distributed load equal to the GHBMC body weight and first principal stress (which is also the maximum principal stress) was computed. Results: All simulations were stable and completed with no errors. In the baseline anatomic configuration, the addition of fluid between the tibia, fibula and talus reduced the maximum principal stress measured in the distal tibia at maximum load from 31.3 N/mm2 to 11.5 N/mm2. Following 1 mm lateral translation of the talus and fibula there was a modest 30% increase in the maximum stress in fluid cases. Qualitatively, translation created less high stress locations on the tibial plafond when fluid was incorporated in the model (Figure 1). Conclusion: The findings in this study demonstrate a potential role for synovial fluid in distributing stresses within the ankle that has not been considered in historical dry cadaveric studies. The increase in maximum stress predicted by simulation of an ankle with fluid is less than half that projected by cadaveric data, indicating a protective effect of fluid in the injured state. The trends demonstrated by these simulations suggest that bony alignment and fluid in the ankle joint change loading patterns on the distal tibia and should be accounted for in future experiments.

Stress Analysis of Dongjiang Arch dam by Finite Element Method under Different Concrete Elastic Modulus and High-Low Temperature Seasons

Elastic modulus and temperature are the main influences of dam stress. In order to study the Dongjiang dam stress for crack controlling, the critical parts stress of dam under different elastic modulus and high-low temperature seasons is analyzed by the finite element method. The results show that: (1) the arch crown and abutment principal tensile stress at upstream face and principal compressive stress at downstream face under high temperature season are greater than the calculation results under low temperature season for the whole at the normal storage water level; (2) the influence on stress caused by elastic modulus are more significant under high temperature season compared to low temperature season at arch crown and abutment, the maximum stress increase with the increasing of elastic modulus. (3) Dongjiang arch dam should pay more attention to the safety control under high temperature season and surface crack prevention and control work in low temperature season.

High shear stress relates to intraplaque haemorrhage in asymptomatic carotid plaques

Background and aimsCarotid artery plaques with vulnerable plaque components are related to a higher risk of cerebrovascular accidents. It is unknown which factors drive vulnerable plaque development. Shear stress, the frictional force of blood at the vessel wall, is known to influence plaque formation. We evaluated the association between shear stress and plaque components (intraplaque haemorrhage (IPH), lipid rich necrotic core (LRNC) and/or calcifications) in relatively small carotid artery plaques in asymptomatic persons. MethodsParticipants (n = 74) from the population-based Rotterdam Study, all with carotid atherosclerosis assessed on ultrasound, underwent carotid MRI. Multiple MRI sequences were used to evaluate the presence of IPH, LRNC and/or calcifications in plaques in the carotid arteries. Images were automatically segmented for lumen and outer wall to obtain a 3D reconstruction of the carotid bifurcation. These reconstructions were used to calculate minimum, mean and maximum shear stresses by applying computational fluid dynamics with subject-specific inflow conditions. Associations between shear stress measures and plaque composition were studied using generalized estimating equations analysis, adjusting for age, sex and carotid wall thickness. ResultsThe study group consisted of 93 atherosclerotic carotid arteries of 74 participants. In plaques with higher maximum shear stresses, IPH was more often present (OR per unit increase in maximum shear stress (log transformed) = 12.14; p = 0.001). Higher maximum shear stress was also significantly associated with the presence of calcifications (OR = 4.28; p = 0.015). ConclusionsHigher maximum shear stress is associated with intraplaque haemorrhage and calcifications.

Mechanical behaviour analysis of a buried steel pipeline under ground overload

Abstract Ground overload is one of the most important factors that threaten the safe operations of oil and gas pipelines. The mechanical behaviour of a buried pipeline under ground overload was investigated using the finite element method in this paper. The effects of the overload parameters, pipeline parameters and surrounding soil parameters on the stress–strain response of the buried pipeline were discussed. The results show that the maximum von Mises stress appears on the top of the buried pipeline under the loading area when the ground load is small, and the stress distribution is oval. As the ground load increases, the maximum stress increases, and the high stress area extends. The von Mises stress, plastic strain, plastic area size, settlement and ovality of the buried pipeline increase as the ground load and loading area increase. The buckling phenomenon of the no-pressure buried pipeline is more serious than the pressure pipeline. As the internal pressure increases, the high stress area and the maximum plastic strain of the buried pipeline first decrease and then increase, the settlement of the buried pipeline increases, and the ovality decreases. The von Mises stress, maximum plastic strain, settlement and ovality of the buried pipeline decrease with increasing buried depth, the surrounding soil's elasticity modulus, Poisson's ratio and cohesion. The maximum von Mises stress, high stress area, the maximum plastic strain, plastic area and ovality increase as the diameter–thickness ratio increases. The critical diameter–thickness ratio is 60, and the settlement of the buried pipeline first increases and then decreases as the diameter–thickness ratio increases. Finally, a protective device of the buried pipeline is designed for preventing ground overload. It can be repaired in a timely manner without stopping the transmission of oil and gas and widely used in different locations because of its simple structure and convenient installation.

CFD modelling of electro-osmotic permeate flux enhancement in spacer-filled membrane channels

Electro-osmosis has the potential to reduce concentration polarisation (CP) because it induces the movement of fluid in the vicinity of membrane, thus improving mixing within the boundary layer and enhancing mass transfer. Computational Fluid Dynamics (CFD) is used to simulate steady and unsteady electro-osmotic flow (EOF) in 2D spacer-filled channels, using the Helmholtz-Schmoluchowski slip velocity approximation. The results show that mass transfer enhancement due to EOF is larger in spacer-filled channel than in empty channels. For the steady EOF, the simulation results show that uniform slip velocity reduces the development of stagnant and high concentration regions near spacer filaments when the slip velocity direction is away from the spacer. For unsteady EOF in spacer-filled channels, the simulation results show that an oscillating slip velocity has the potential to induce vortex shedding. This occurs when a resonant slip velocity frequency is used for Reynolds numbers near the transition from steady to unsteady flow. EOF induced vortex shedding due to the resonant slip velocity results in significant increase in maximum wall shear stress along the membrane, therefore potentially delaying the onset of fouling. The data also shows that at the same permeate flux, EOF at the resonant slip velocity frequency results in a significantly lower Power number (a proxy for pumping energy) than the case without EOF.

Molecular mechanisms in deformation of cross-linked hydrogel nanocomposite

The self-folding behavior in response to external stimuli observed in hydrogels is potentially used in biomedical applications. However, the use of hydrogels is limited because of its reduced mechanical properties. These properties are enhanced when the hydrogels are cross-linked and reinforced with nanoparticles. In this work, molecular dynamics (MD) simulation is applied to perform uniaxial tension and pull out tests to understand the mechanism contributing towards the enhanced mechanical properties. Also, nanomechanical characterization is performed using quasi static nanoindentation experiments to determine the Young's modulus of hydrogels in the presence of nanoparticles. The stress–strain responses for chitosan (CS), chitosan reinforced with hydroxyapatite (HAP) and cross-linked chitosan are obtained from uniaxial tension test. It is observed that the Young's modulus and maximum stress increase as the HAP content increases and also with cross-linking process. Load displacement plot from pullout test is compared for uncross-linked and cross-linked chitosan chains on hydroxyapatite surface. MD simulation reveals that the variation in the dihedral conformation of chitosan chains and the evolution of internal structural variables are associated with mechanical properties. Additional results reveal that the formation of hydrogen bonds and electrostatic interactions is responsible for the above variations in different systems.