Nonlinear Material Properties Research Articles

Prediction and compensation of process-induced distortions for L-shaped 3D woven composites

A physics-based numerical model for prediction and compensation of the process-induced distortion of 3D woven composite (3DWC) is presented. A new tool-part interaction modelling method for the Resin Transfer Molding process is developed, in which the nonlinear material properties and non-thermoelastic distortion are taken into account. Flat and L-shaped 3DWC parts were fabricated and the process-induced distortions were evaluated. Adopting the input values determined by the warpages of flat parts, the spring-in of L-shaped parts predicted by the model is consistent with the experimental measurements. Based on the model, it is found that taking the warpage/spring-in of the uncompensated parts as the compensation value will result in a deviation between the manufactured parts and the nominal shape. An improved comprehensive compensation procedure is proposed and applied to an L-shaped 3DWC part. The result shows that the dimensional precision of the part can be significantly improved by the compensation process.

Study of bonding zone composite reinforced structures

A bonding zone between elements of layered composite concrete structure was investigated. Results of stress-strain state, nonlinear deformation, and crack resistance of this zone are presented. The bonding zone simulation was performed using the developed methodology based on the finite element method. The problem was solved in a nonlinear formulation using elements with nonlinear material properties and one-side contact elements. A fragment of a layered structure made of two concretes with different strength and under the action of shear forces was considered. Based on the available experimental data, shear stiffness of the bonding zone was calculated. The simulation of the deformation process for the composite structure was performed taking into account its nonlinear deformation and consideration of the cracking process up to the moment of its complete failure. The obtained results of are compared with experimental data. The necessity of using the actual strength and deformation characteristics of the shear of the bonding zone when modeling the deformation process and evaluating the ultimate breaking load is shown.

Experimental and analytical study of the mechanical and flexural behavior of hybrid fiber concretes

The use of fibers in Reinforced Concrete (RC) structures may improve the properties of concrete; like reducing the shrinkage strain and increasing the tensile, flexural, and bond strength. This article presents an experimental and Finite Element (FE) analysis of hybrid fiber concretes. Three types of hybrid fibers were utilized, namely, hybrid steel-glass, steel-basalt, and glass-basalt fibers. For compressive and tensile strength tests, a total of forty-eight cubes and forty-eight cylinders were casted. The result obtained shows that fibers addition to concrete improves the compressive and tensile strengths. An increasing of the compressive strengths of 48% was recorded when compared with concrete without fibers. For flexural strength test, two RC beams were casted and tested up to failure under two-point loading. The beams have an identical size of 1500 × 150 × 200 mm. A nonlinear FE models were developed using ANSYS software to analyze the two hybrid RC beams. Nonlinear material properties, resulted from the experimental test, were defined in the FE models. The results obtained from FE and experimental analyses were compared and close correlations were found between them.

A micro-modeling approach for the prediction of TRM bond performance on curved masonry substrates

Retrofitting of arches, vaults and domes is needed for vulnerability mitigation of historical structures. Lately, the external application of composite materials embedded within an inorganic matrix addressed the compatibility issues related to FRP applications. Great efforts have been made for a correct identification of tensile and bond properties of TRM reinforcement, but scarce data are available for understanding the effect of curvature in debonding. This paper provides a numerical approach that enables to predict the reinforcement performance on curved masonry elements, when the same is designed without having specific single lap shear tests for the adopted materials. Such an approach relies on a separate modeling of each constituent material of the reinforcement and the substrate: matrix, fibers and the interface between them, and bricks and mortar joints. The FE-based software Abaqus is used for the simulations, addressing the non-linear material properties by means of the CDP constitutive model. In order to calibrate and validate the proposed numerical approach, experimental data are used and through a comparison of the load–displacement curves obtained the capabilities of the method are discussed. Finally, an extension of such approach to curvatures not experimentally tested is presented, opening the way to future applications of the approach.

Computational analysis of failure mechanisms in composite sandwich space structures subject to cyclic thermal loading

Accurate prediction of the thermal stability and durability of composite sandwich materials used in space structures remains a challenge due to the variability of thermal related material coefficients at different temperatures and the extensive use of adhesively bonded joint fittings. This paper presents an investigation into the thermomechanical performance of complex honeycomb core composite sandwich structures with bonded fittings exposed to extreme temperature ranges. First, detailed analyses are conducted to investigate the failure and predict the intrinsic nonlinear material properties of a specific aerospace-grade aluminum honeycomb core and carbon-epoxy composite face sheet. Sandwich panels with two types of bonded fittings are chosen to investigate nonlinear effects such as shear buckling and plastic deformation in the honeycomb core, and the progressive damage response in composite skins under different loading conditions. The nonlinear properties and modeling strategies are then incorporated in the subsequent analysis of a spacecraft’s thrust tube sandwich structure subject to cyclic thermal loading. The predicted damage and failure in the thrust tube section with an adhesively bonded cup fitting correlated with experimental observations. The current methodology offers a consistent technique for investigating the thermomechanical performance of sandwich structures with other configurations of bonded joints and fittings.

Fused polycyclic compounds: Synthesize, enhancing TPA cross-section by modifying torsional multiple ring

Abstract Four fused polycyclic compounds (DNBT, DNTB, DNPY, and DNNM) with different substituents were designed and synthesized to achieve excellent nonlinear optical materials. Broadband reverse saturation absorption performance based on TPA was carried out by Z-scan. Transient absorption spectrum showed that the different substituents can significantly regulate the ultrafast kinetic processes of their excited states. The relationship between excited states charge structure and nonlinear optical properties were studied by density functional theory (DFT) and sum over states (SOS) model. TPA of these compounds is modulated by local excitation in DBPy and TA fragments. Intra-molecular charge transfer weakens the TPA cross-section. These compounds are potential optical limiting (OL) materials in visible light range. The clear mechanism show that the nonlinear optical properties of organic materials can be improved purposefully through theoretical and experimental methods.

Synthesis and Characterization of NLO Material L-Valine L-Valinium Perchlorate Monohydrate for Photonics Applications

L-valine L-valinium perchlorate monohydrate single crystal has been synthesized by slow evaporation technique at room temperature. The crystal structure and space group of the crystal were confirmed by single crystal X-ray diffractometer. Optical behavior of the crystal was analyzed by using UV-visible spectrophotometer. Thermal stability was discussed by using thermo gravimetric analysis. Mechanical strength of the grown crystal was studied using Vickers microhardness tester. Nonlinear optical property was explored to confirm the second harmonic generation efficiency of the grown crystal. These preliminary investigations suggest that the title compound can serve as a potential material for photonics applications. Full Text: PDF ReferencesD. J. Williams, "Nonlinear Optical Properties of Organic and Polymer Materials" (ACS Symposium series 233, American Chemical Society, Washington, DC, 1983). CrossRef K. Bouchouit, Z. Sofiani, B. Derkowska, S. Abed, N. Benali-cherif, M. Bakasse and B. Sahraoui, "Investigation of crystal structure and nonlinear optical properties of 2-methoxyanilinium nitrate", Opt. Commun. 278, 180 (2007), CrossRef K. Bouchouit, H. Bougharraf, B. Derkowska-zielinska, N. Benali-cherif and B. Sahraoui, "Reversible phase transition in semi-organic compound p-Nitroanilinium sulfate detected using second harmonic generation as a tool", Opt.Mater. 48, 215 (2015), CrossRef J. H. Joshi, S. Kalainathan, M. J. Joshi and K. D. Parikh, "Crystal growth, spectroscopic, second and third order nonlinear optical spectroscopic studies of L-phenylalanine doped ammonium dihydrogen phosphate single crystals", Arab. J. Chem. 13, 5018 (2020), CrossRef A. Vijayakumar, A. Ponnuvel and A. Sasikala, "Growth and characterization of α and β form of L-histidine dihydrochloride single crystals", Mater. Today 14, 338 (2019), CrossRef C. Usha, R. Sathakuamri, Lynnette Joseph, D.Sajan, R.Meenakshi, and A.Sinthiya, "Growth and combined experimental and quantum chemical study of glycyl-L-Valine crystal", Heliyon 5, e01574 (2019), CrossRef P. Maadeshwaran and J. Chandrasekaran, "Synthesis, growth and characterization of l-valine cadmium chloride monohydrate—A novel semiorganic nonlinear optical crystal", Optik 122, 1128 (2011) CrossRef S. Pandiyaran, M. Umadevi, R. K. Rajaraman and V. K. Ramakrishnan, "Infrared and Raman spectroscopic studies of l-valine l-valinium perchlorate monohydrate", Spectrochim. Act A Mol. 62, 630 (2005) CrossRef S. Pandiarajan, B. Sridhar and R. K. Rajaram, "L-Valine L-valinium perchlorate monohydrate", Acta Crystallogr. E, 57, 0466 (2001) CrossRef M. Lydia Caroline and S. Vasudevan, "Growth and characterization of l-phenylalanine nitric acid, a new organic nonlinear optical material", Mater. Lett. 63, 41 (2009) CrossRef J. Tauc, R. Grigorovici and A. Vancu, "Optical Properties and Electronic Structure of Amorphous Germanium", Phy. Solid. Stat. 15, 627 (1966), CrossRef J. Tauc, A. Menth and D.L. Wood, "Optical and Magnetic Investigations of the Localized States in Semiconducting Glasses", Phys. Rev. Lett. 25, 749 (1970) CrossRef B. Thirumalaiselvam, R. Kanagadurai, D. Jayaraman and V. Natarajan, "Growth and characterization of 4-methyl benzene sulfonamide single crystals", Opt.Mater. 37, 74 (2014) CrossRef J. Bowman and M. Bevis, "The evaluation of the structure and hardness of processed plastics by the Vickers microhardness test", Colloid Polym. Sci. 255, 954 (1977) CrossRef S. K. Kurtz and T. T. Perry, "A Powder Technique for the Evaluation of Nonlinear Optical Materials", J. Appl. Phy. 39, 3798 (1968) CrossRef M. Prakash, D. Geetha and M. Lydia Caroline, "Crystal growth, structural, optical, spectral and thermal studies of tris(l-phenylalanine)l-phenylalaninium nitrate: A new organic nonlinear optical material", Spectrochim. Act A Mol. 81, 48 (2011) CrossRef

Fitness-for-service of open-top storage tanks subjected to differential settlement

A method for evaluating the mechanical integrity of open-top cylindrical storage tanks subjected to a differential settlement is given. The settlement profile underneath the bottom circumference of the tank shell can be transformed into different harmonic components using the Fourier transformation. The existing method in American Petroleum Institute’s standard API 653, which is currently used by the industry in North America, does not differentiate the effect of different harmonic components. Nevertheless, the proposed method evaluates a cumulative damage factor by considering the effects of first five harmonic components individually. The paper further discusses other limitations of the existing method in API 653 document. Numerous finite element analysis (FEA) simulations are conducted to formulate and validate the proposed method by employing geometric nonlinear algorithm with nonlinear plastic material properties (GMNA) in ABAQUS finite element software. The trend for limiting settlement values with respect to different harmonic components under consideration and different tank geometries are discussed. The proposed method is validated by performing FEA using four actual settlement data profiles on different tank geometries. Lastly, the comparison is drawn between the FEA results, the existing API 653 method and the proposed method. The results of the allowable settlement indicate that the existing method is not consistent with the FEA findings. For some of the actual settlement data, the existing method results in overly conservative values and for others it gives non-conservative values. Thus, the existing method may not capture the true behavior of tanks under settlement and needs modifications. The results of allowable settlement from the proposed method are found to be consistent with the FEA results for all different settlement data and tank geometries. Therefore, it is recommended that the new method is used instead of the existing method.

Effective hydro-mechanical material properties and constitutive behaviors of meso-structured RVE of saturated granular media

In the framework of the second-order concurrent computation homogenization method for saturated granular material, meso-structured RVE (Representative Volume Element) is modeled as a compact assembly of saturated discrete particles. The boundary conditions imposed on the RVE are comprised of the two parts: (1) the boundary displacements and pressures prescribed by downscaled macroscopic strain variables and pore pressure, and (2) constrained fine scale fluctuations of mesoscopic hydro-mechanical variables expressed in terms of periodic boundary conditions.The present paper focuses on the estimation of effective hydro-mechanical material properties and constitutive behaviors of meso-structured RVE of saturated discrete particle assembly via a proposed homogenization procedure. To achieve this target, a novel scheme for determining and imposing periodic boundary conditions on peripheral particles contacting with the RVE boundary of saturated discrete particle assembly is proposed.Numerical results demonstrate performances and capabilities of the proposed scheme in estimating effective hydro-mechanical non-linear material properties and predicting hydro-mechanical constitutive behaviors of saturated granular materials evolving with loading histories. They also demonstrate the significance and necessity of imposing periodic boundary conditions on the RVE in proper prediction of effective hydro-mechanical material properties and constitutive behaviors.

Nonlinear vibration analysis of fiber reinforced composite cylindrical shells with partial constrained layer damping treatment

This research proposes a novel analytical model capable of accurately predicting the strain-dependent characteristics of fiber reinforced composite shells (FRCSs) with partial constrained layer damping (CLD) treatment by considering the nonlinearities of fiber reinforced composite and viscoelastic materials simultaneously. The nonlinear material properties are represented based on Jones-Nelson nonlinear theory, energy-based strain energy method, and complex modulus method. Then, the governing equations of motion for FRCSs are developed via Ritz method, and the identification procedure of nonlinear fitting parameters is also presented. By taking a T300 carbon fiber/epoxy resin cylindrical shell with partial CLD patches as an example, a series of experiments are carried out to validate the proposed modeling approach. Finally, the effects of material properties on nonlinear vibration behaviors of FRCSs covered with partial CLD patches are evaluated. Comparisons show that the proposed nonlinear model is more accuracy than that without considering strain dependence, where the maximum errors between the proposed model and measured data for natural frequencies, damping ratios and resonant response are 6.9%, 11.3%, and 11.2%, respectively.

Effect of surface oxidation on nonlinear optical absorption in WS2 nanosheets

Controlling nanosheet size and understanding size-dependent surface oxidation are of quite importance for the nonlinear optical properties of two-dimensional materials. Herein, size-separation of WS2 nanosheets was prepared successfully using liquid phase exfoliation and a gradient centrifugation method. We confirmed the higher surface oxidation with the decrease of nanosheet size by both high-resolution X-ray photoelectron spectroscopy and Raman spectroscopy. To investigate the effect of size-dependent surface oxidation on nonlinear optical properties in WS2, Z-scan technique equipped with 800 nm femtosecond laser was used. We observed the conversion between saturable absorption and reverse saturable absorption in WS2 dispersions as well as the decrease of saturable absorption in WS2 films due to the increase of reverse saturable absorption contribution of WO3. Energy-level model based on type II WS2/WO3 heterostructure was put forth to understand nonlinear optical absorption of the oxidized WS2. The results show that charge transportation from WS2 to WO3 increases the reverse saturable absorption contribution in WO3 while decreases the saturable absorption in WS2. The results pave the way to design desirable nonlinear optical devices by controlling size with different level of surface oxidation.

Consistent and Efficient Modeling of the Nonlinear Properties of Ferroelectric Materials in Ceramic Capacitors for Frugal Electronic Implants

In recent years, the development of implantable electronics has been driven by the motivation to expand their field of application. The main intention is to implement advanced functionalities while increasing the degree of miniaturization and maintaining reliability. The intrinsic nonlinear properties of the electronic components, to be used anyway, could be utilized to resolve this issue. To master the implementation of functionalities in implantable electronics using the nonlinear properties of its electronic components, simulation models are of utmost importance. In this paper, we present a simulation model that is optimized in terms of consistency, computing time and memory consumption. Three circuit topologies of nonlinear capacitors, including hysteresis losses, are investigated. An inductively coupled measurement setup was realized to validate the calculations. The best results were obtained using the Trapezoid method in ANSYS with a constant step size and a resolution of 500 k points and using the Adams method in Mathcad with a resolution of 50 k points. An inductive coupling factor between 7% and 10% leads to a significant improvement in consistency compared to lower coupling factors. Finally, our results indicate that the nonlinear properties of the voltage rectifier capacitor can be neglected since these do not significantly affect the simulation results.

Nonlinear thermomechanical buckling of sandwich FGM oblique stiffened plates with nonlinear effect of elastic foundation

In this article, the nonlinear thermomechanical buckling behaviors of sandwich functionally graded plates subjected to an axial compression and external pressure are analytically analyzed resting on nonlinear elastic foundation. Assuming that the plates are reinforced by oblique stiffeners and rested on nonlinear elastic foundation. The formulations are established using the higher-order shear deformation theory taking into account the geometrical nonlinearity of von Kármán. The Lekhnitskii’s smeared stiffener technique is developed for shear deformable oblique stiffener system using the coordinate transformation technique with both mechanical and thermal terms. The Galerkin method is utilized to obtain the nonlinear algebraically equation system, then, solve it to determine the explicit expressions of critical buckling loads and postbuckling load–deflection curves. Numerical results show the effects of temperature, nonlinear elastic foundation, stiffeners, and material and geometrical properties on nonlinear behaviors of plates.

Extracting non-linear viscoelastic material properties from violently-collapsing cavitation bubbles

Determination of high strain-rate constitutive material parameters from highly compliant, non-linear materials including hydrogels and soft tissues remains a significant challenge. To address this challenge we recently developed a laser-based Inertial Microcavitation Rheometry (IMR) technique, capable of constitutively characterizing soft materials at ultra-high strain-rates (O(103)∼O(108)s−1). This technique utilizes spatially-focused, and temporally-resolved, single cavitation bubbles in conjunction with a theoretical framework for determining the non-linear viscoelastic material properties of the surrounding soft material.Here, by advancing our spatiotemporal imaging capability and tracking the motion of native material features close to the inertially cavitating bubble, we find significant deviation from the IMR predicted material displacements at a critical material Mach number of 0.08, marking the transition to violent collapse. Interestingly, this critical Mach number appears to be almost independent of the material properties of the surrounding hydrogel. We show that through proper temporal resolution of the cavitation dynamics, all of the highly nonlinear viscoelastic properties of the surrounding material can still be uniquely determined from just the first expansion and collapse cycle alone, as long as the local Mach number is below the critical threshold. Furthermore, we show that the inclusion of a higher order strain stiffening term on the rate-dependent non-linear spring can lead to better estimation of the material properties and full recovery of the equilibrium shear modulus, which was not possible with previous nonlinear neo-Hookean Kelvin–Voigt model formulations. Thus, the developments presented here significantly expand the applicability and robustness of IMR for accurately determining the rate-dependent, finite deformation constitutive behavior of soft materials.

Synthesis, structural analysis, upconversion luminescence and magnetic properties of Ho3+/Yb3+ co-doped GdVO4 nanophosphor

Herein, we report a magneto-luminescent nanoparticle (NPs) GdVO4: Ho3+, Yb3+ which is paramagnetic in nature and can emit red emission under NIR excitation. Such magneto-luminescent material may serve potentially as a bi-functional probe (optical/magnetic) for bio-imaging applications. Material has been synthesized using a facile sol-gel technique. The structure and morphology of the synthesized NPs were investigated employing X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy techniques. Co-doped GdVO4 NPs crystalizes into tetragonal crystal structure with space group I41/amd. Nonlinear photon upconversion properties of co-doped materials were studied under 980 nm NIR laser excitation. The intense upconversion emission peaks arise at ~543 nm and ~653 nm due to electronic transition (5S2→ 5I8) and (5I5→5I8) of Ho3+, respectively and Yb3+ act as the sensitizer. Optimized concentration i.e. 1 mol% Ho3+/10 mol% Yb3+ gives prominent red emission. From the laser input power dependence studies, three-photon involvements were observed for the green and red bands. A possible mechanism for energy transfer and for possible transitions is also suggested and discussed in details using an energy level diagram. In addition to the excellent optical emission, the NPs show paramagnetic behaviour as well which was confirmed by vibrating sample magnetometer (VSM) studies. Since the prepared nano phosphor materials show the brilliant red upconversion emission under NIR excitation. This may be useful in red color emitter in the display such as LEDs and in bioimaging of the biomolecules. Also, Gd3+ based host gives its paramagnetic character which further promotes its utility in MRI applications.

Forced vibrations of high-rise buildings

Studies were conducted to analyze the behavior of a high-rise structure on various kinematic effects, taking into account the real geometry, dissipative and nonlinear properties of the structure material. A generalized approach was developed for the dynamic calculation of high-rise structures, and the frequency response characteristics at various points of the structure were built. It was found that nonlinear properties are manifested when the impact can cause significant strain in the structure. This applies not only to the magnitude of the impact intensity, but also to its frequency content. If a non-linearly elastic strain of the material is manifested in the structure, then this leads to a decrease in the amplitudes of points displacements and to an increase in oscillation period compared to a linearly elastic structure under similar kinematic effects.

Influence of temperature- and strain rate-dependent viscoplastic properties of polyoxymethylene on the thermo-mechanical response of a steel-polyoxymethylene spur gear pair

The nonlinear material properties of thermoplastics like polyoxymethylene (POM) can influence the thermo-mechanical response of polymer gears to applied running loads. In the presented study, the non-elastic strain rate- and temperature-dependent mechanical characteristics of POM are examined, along with their influence on the mechanical response of the polymer gear at the tooth root and contact interface, and the resulting heat generation driving the commonly exhibited temperature rise during gear meshing/running. A detailed experimental study of these properties was conducted, employing standardized and partly customized tensile and bending tests. Using a suitable viscoplastic constitutive material model, calibrated based on the obtained experimental results, a numerical structural-contact analysis of the gear meshing process was performed, which could subsequently be used for a more detailed evaluation of the generated frictional heat and resulting temperature rise during gear running. While a significant influence of the viscoplastic material properties on the mechanical contact response and the flash temperature rise on the POM gear was identified, no major impact on the long term nominal temperature rise was recognized.

Calibration of a Hypoplastic Constitutive Model with Elastic Strain Range for Firoozkuh Sand

A series of laboratory experiments on Firoozkuh sand were conducted followed by a set of numerical simulations to determine the parameters of a general hypoplastic constitutive model for sand. This model describes inelastic and incrementally nonlinear material properties without a yield surface and detached strain increments in the elastic and plastic portions that is used to accurately simulate soil behavior for small and large strains and unloading–reloading paths. The general models are salient and the model requires unique constitutive constant values for all densities of a particular soil at all pressures. The 13 hypoplastic parameters used were calibrated through standard laboratory monotonic and cyclic triaxial and oedometer tests. Additional undrained triaxial and cyclic triaxial testing data that had not been used in the calibration process were used to validate the parameters.

Carbon nanotube versus graphene in modifying the electrical and optical properties of organic nonlinear optical material

4-N,N-dimethylamino-4′-N′-methyl-stilbazolium tosylate (DAST) is an important organic nonlinear optical material, but its applications in electronic devices are limited by its poor electrical conductivity. To tackle this problem, DAST–carbon nanotube (CNT) and DAST–graphene (G) binary composite films, as well as DAST–CNT–G ternary composite films were prepared and compared. Results indicate that both the electrical and optical properties of DAST can be effectively modified by CNT or G. Moreover, electrical percolation phenomena are observed in the DAST-based binary composite films at ~ 6.7 wt% CNT or ~ 2.0 wt% G. The as-prepared DAST–CNT films show higher electrical conductivity, while the DAST–G films exhibit higher temperature coefficient of resistance. Particularly, comprehensive optimal properties are observed in the DAST–CNT–G composite films, combining both advantages of DAST–CNT and DAST–G binary composite films, revealing the synergistic effects of CNT and G in the resultant ternary composite films.

A Comprehensive Engineering Analysis of Left Heart Dynamics After MitraClip in a Functional Mitral Regurgitation Patient.

Percutaneous edge-to-edge mitral valve (MV) repair using MitraClip has been recently established as a treatment option for patients with heart failure and functional mitral regurgitation (MR), which significantly expands the number of patients that can be treated with this device. This study aimed to quantify the morphologic, hemodynamic and structural changes, and evaluate the biomechanical interaction between the MitraClip and the left heart (LH) complex of a heart failure patient with functional MR using a fluid-structure interaction (FSI) modeling framework. MitraClip implantation using lateral, central and double clip positions, as well as combined annuloplasty procedures were simulated in a patient-specific LH model that integrates detailed anatomic structures, incorporates age- and gender-matched non-linear elastic material properties, and accounts for mitral chordae tethering. Our results showed that antero-posterior distance, mitral annulus spherecity index, anatomic regurgitant orifice area, and anatomic opening orifice area decreased by up to 28, 39, 52, and 71%, respectively, when compared to the pre-clip model. MitraClip implantation immediately decreased the MR severity and improved the hemodynamic profile, but imposed a non-physiologic configuration and loading on the mitral apparatus, with anterior and posterior leaflet stress significantly increasing up to 210 and 145% during diastole, respectively. For this patient case, while implanting a combined central clip and ring resulted in the highest reduction in the regurgitant volume (46%), this configuration also led to mitral stenosis. Patient-specific computer simulations as used here can be a powerful tool to examine the complex device-host biomechanical interaction, and may be useful to guide device positioning for potential favorable clinical outcomes.