Finite Element Method Calculations Research Articles

Fretting Behavior of WC-Co-Cr Coatings Against QT Steel in Bolted Joint

Fretting damage on contacting surfaces introduces major challenges in mechanical assemblies. Thermal sprayed hardmetal coatings are extensively used for surface modification in tribological applications under demanding conditions and may also be subjected to fretting-inducing loading. In the present work, the fretting behavior of High Velocity Oxy-Fuel (HVOF) and High Velocity Air–Fuel (HVAF) sprayed WC-10Co-4Cr coatings against quenched and tempered (QT) steel was studied by using a single bolt joint-type fretting experiment. This experimental approach was selected to obtain realistic data on the fretting fatigue performance of the contact pairs (both coating-to-steel and coating-to-coating). Experimental results were completed with continuum-scale linear elastic finite element method (FEM) calculations.

(152) Energy Absorption Simulation During Low Intensity Shockwave Therapy

Abstract Introduction Low intensity shockwave therapy (LiSWT) has been used to treat erectile dysfunction since 2010 by inducing mechanotransduction. The greater the shockwave energy absorbed in cavernosal erectile tissue, the greater the opportunity for mechanotransduction regenerative mechanisms to occur and improve erectile function. Effectiveness of LiSWT depends, in part, on applied energy (mJ/mm2) and number of applications (total shocks). Although intensity of LiSWT energy cannot be arbitrarily increased due to side effects, energy absorption may be improved by performing treatment to an erect vs flaccid penis. Intracavernosal pressure and penile volume are both determinants of velocity of the energy wave in tissue and therefore absorption of shockwave energy in tissue. Intracavernosal penile pressure when erect (100 mmHg) is 16-fold higher than flaccid (6 mmHg), and blood volume when erect (142.6 cm3) is >2 times more than flaccid (62.18 cm3), therefore LiSWT in the erect state with larger blood-filled lacunar spaces should be associated with greater shockwave energy absorption. Use of a symmetry-matched secondary reflector can further increase the energy absorption of each applied shockwave by reflecting the wave back. Objective The aim of this study was to perform a simulation of energy absorption during LiSWT with a reflector in both the flaccid and erect penis. Methods This energy model used the MTS UroGold electrohydraulic shockwave device [Softwave TRT]. When sound waves pass through an interface between 2 media with different impedances, sound propagation can be significantly altered. If impedances of the media are different, part of the sound energy is reflected into the incident medium; the rest of the sound energy is transferred to the second medium. Sound propagation in tissue can be illustrated via computer simulation by mathematically calculating the damping and deflection of the sound wave by different tissue structures. Finite Element Method (FEM) simulation models are particularly suitable for the mathematical description of complex processes of shockwave propagation, such as in the flaccid and erect penis. Based on results, a “prediction” of propagation of LiSWT in tissue is possible. This patient-specific procedure is based on consideration of individual anatomical structures: corporal lacunar spaces and physical-acoustic laws. For FEM modeling of LiSWT propagation, program systems ANSYS, MATLAB and PZFLEX/ONSCALE were used. Results Using the FEM calculation model of the simulation analyses, the shockwave pulse is applied at the bottom edge of the model (Fig 1). It propagates through the erect (Fig 2a) and flaccid (Fig 2b) states, with the most energy absorption in the erect penis, shown in red. The effect of increased penile pressure on energy absorption with a constant volume is shown in Fig 3. Conclusions More energy is absorbed in cavernosal tissue during erection than in the flaccid state, with a further increase in absorption with use of a symmetric reflector. This provides greater opportunity for beneficial mechanotransduction regenerative mechanism due, in part, to increased intracavernosal pressure and tissue volume with larger blood-filled lacunar spaces during erection. LiSWT to treat erectile dysfunction should be more effective when performed in the erect state utilizing a reflector. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: MTS Medical, Softwave TRT.

Relative Entropy Application to Study the Elastoplastic Behavior of S235JR Structural Steel.

The main issue in this work is to study the limit functions necessary for the reliability assessment of structural steel with the use of the relative entropy apparatus. This will be done using a few different mathematical theories relevant to this relative entropy, namely those proposed by Bhattacharyya, Kullback-Leibler, Jeffreys, and Hellinger. Probabilistic analysis in the presence of uncertainty in material characteristics will be delivered using three different numerical strategies-Monte Carlo simulation, the stochastic perturbation method, as well as the semi-analytical approach. All of these methods are based on the weighted least squares method approximations of the structural response functions versus the given uncertainty source, and they allow efficient determination of the first two probabilistic moments of the structural responses including stresses, displacements, and strains. The entire computational implementation will be delivered using the finite element method system ABAQUS and computer algebra program MAPLE, where relative entropies, as well as polynomial response functions, will be determined. This study demonstrates that the relative entropies may be efficiently used in reliability assessment close to the widely engaged first-order reliability method (FORM). The relative entropy concept enables us to study the probabilistic distance of any two distributions, so that structural resistance and extreme effort in elastoplastic behavior need not be restricted to Gaussian distributions.

Stable Slope Design Based On Limit Equlibrium Method (Lem) And Finite Element Method (Fem) At Pit X, Lahat, South Sumatra

Coal mining process using open pit mining method is closely related to slope stability. A slope whose stability is disturbed will have a higher potential for landslides. The slope stability analysis in this research is conducted by Limit Equilibrium Method (LEM) with the calculation of Morgenstern-pice slice method and Finite Element Method (FEM) with the calculation of Shear Strength Reduction. The highwall simulation was modeled with a Bench height of 10 meters, Bench width of 6.5 meters and bench tilt angle varying between 30°, 45°, 60° and groundwater condition using steady state FEA. From the results of the LEM analysis on the highwall with a bench tilt angle of 30 °, 45 °, 60 ° has a safety factor value of 1.005; 0.76; 0.584. While the results of the FEM analysis on the highwall with a bench tilt angle of 30 °, 45 °, 60 ° have a Strength Reduction Factor value of 0.98; 0.72; 0.57. Comparison of the safety factor values of the two methods has an average difference of 1-2%. This is because the FEM takes into account the stress-strain in the material which describes how the material behaves. The stable slope design based on LEM is a highwall slope with a Bench slope angle of 22° which has a safety factor value of 1.478 and based on FEM is a highwall slope with a Bench slope angle of 22° which has a Strength Reduction Factor value of 1.42.

Evaluation of the Applicability of Digital Photogrammetry-Based Initial Imperfections on NLFEM Ultimate Strength Analysis of Ship- Type Stiffened Plates

In this study, the effects of initial imperfections on the ultimate strength values of ship-type stiffened plate structures are discussed and analysed from the point of view of how the initial imperfection forms are obtained. Ship stiffened panels are subjected to complex loading conditions during their operational lifespan. Accurate prediction of their strength and failure modes necessitates a thorough understanding of the effects of various imperfections on their behavior. Two primary sources of initial imperfections are considered: the buckling mode shapes resulting from linear eigenvalue buckling analysis and measurements based on digital photogrammetry. Buckling mode shapes, arising from the manufacturing process are extracted using linear static structural analysis. Digital photogrammetry is employed to capture and quantify imperfections by analysing high-resolution images of the physical structure. Numerical investigation is conducted by incorporating these two types of initial imperfections into non-linear finite element method (NLFEM) calculations. The buckling mode imperfections are applied as geometric perturbations, while the photogrammetry-based imperfections are incorporated as statistically representative deviations from the ideal geometry. Stiffened panel's structural response is analysed under longitudinal uniaxial compression. A new NLFEM project schematic has been utilized instead of the procedure outlined in the technical circular S.P 01/19 by Türk Loydu, which has been discontinued after ANSYS® Workbench™V.2019R2. This is proven by two validation case studies in ANSYS® Workbench™2022R2 version for considering buckling mode initial imperfections. A case study is then conducted using a 3D model of a stiffened plate panel, which is fabricated in a shipyard located in Trabzon, created by Photomodeler V. 2023.3.0.238 employing the digital photogrammetry method.NLFEM analysis is carried out for both initially deflected model after eigenvalue buckling analysis and naturally deflected model after welding operations. The comparative ultimate strength results are quite consistent, and this shows that the digital photogrammetric modelling method can be used in the analysis of ship structural elements.

Investigation of efficiency and temperature dependence in RbGeBr3-based perovskite solar cell structures

This study is centered on the exploration of the inorganic perovskite material RbGeBr3 as an absorbing layer in various configurations of perovskite solar cells (PSCs). The Poisson, continuity, and transport equations are solved using the finite element method for calculation. Systematic variations in the thicknesses of the RbGeBr3 absorber layer and the electron transfer layer are performed, with gold (Au) and silver (Ag) utilized as metal contacts for the electrodes. The study also delves into the impact of temperature variations on the efficacy of these structures. Among the tested configurations, the FTO/TiO2/RbGeBr3/P3HT/Au configuration emerges as the most efficient, achieving a power conversion efficiency of 11.89 %, with a short-circuit current of 14.47 mA/cm2 and an open-circuit voltage of 0.96 V. Additionally, two alternative structures, FTO/ITO/RbGeBr3/PEDOT:PSS/Au and FTO/ITO/RbGeBr3/PEDOT:PSS/Ag, are investigated, yielding comparable power conversion efficiencies of 11.374 %. The findings of this study can serve as valuable insights for the design of more advanced and efficient perovskite solar cells based on mineral perovskite layers.

Analysis of the thermal effect of two external parallel printed circuit board conductors set on a metal base and operating in a space vacuum on each other

Background. The need to analyze the thermal effect of two external parallel conductors is due to an increase in the density of the conductive pattern. For printed circuit boards set on a metal base and operating in the vacuum of space, this need is aggravated by the weakness of the issue's development. 
 Aim. Analysis of the mutual influence of two external parallel printed circuit board conductors set on a metal base and operating in a space vacuum on each other to identify the dependence of their temperature on the distance between them and determine the distance at which this dependence practically disappears.
 Methods. To achieve the purpose, a finite element method calculation implemented in the ANSYS program, the Steady-State Thermal module, was used. Three multilayer printed circuit boards were calculated: 4-layer, 6-layer, 8-layer. The temperature coefficient of resistance was taken into account separately, by recalculation.
 Results. Graphs of the dependence of overheating (the difference between the temperature of the printed conductor and the metal base) on the distance between the printed conductors were constructed. The approximation of the obtained results is carried out. According to the approximated dependencies, the minimum values of the distances between printed conductors are found, at which the cross influence of printed conductors practically disappears. As the thickness of the printed circuit board increases, this distance increases.
 Conclusion. The results obtained can help to assess the influence of neighboring printed conductors in the design of the boards of the onboard equipment of spacecraft.

Fatigue Analysis of a Cracked Shaft: a Finite Element Modeling Approach

Shafts are typically used in sophisticated mechanisms and machinery which highly depend on shafts for rotatory motion which could lead to the failure. In today’s contemporary, damages caused by cracking on mechanical components and structures have increased, causing crack and structural failure. The failure could be examined by the calculation of stress intensity factor (SIF). Once the shaft reaches the critical SIF (SIFIC), the flaw is initiated and has a potential to propagate upon loading. Typically, the flaw would spread in many patterns and tenders to the formation and initiation of different types of cracks. Thus, the objective of this research work is to analyse fatigue cracked shafts. Prediction of crack growth via SIF calculation. SIF is usually adapted to predict the stress intensity near the crack tip where crack propagation occurs. Thus, SIF is used to study and analyse the cracked surface in relation to crack initiation and propagation. The SIF is calculated through finite element method (FEM) since the FEM is capable simulating complex geometry. The SIF is calculated based on the deformation in FEM calculation. The results show the predicted crack propagation and SIF calculation. It is crucial to study the resistance of cracked shafts towards cyclic loading for maintenance preceding and retirement of the structure.

Reliability assessment of composite column according to Monte Carlo Simulation and Latin Hypercube Sampling

When a structural element, like a column, is evaluated for resistance using the finite element method or analytical calculation, all parameters related to the resistance side and action effect are treated as deterministic. Nevertheless, in probabilistic analyses, these parameters are regarded as random variables, which are defined using various distributions like the normal distribution, log-normal distribution, beta, or gamma distribution. Monte Carlo Simulation (MCS) and Latin Hypercube Sampling (LHS) are two sampling methods widely used for generating random samples from statistical distribution. The number of samples generated influences the accuracy of the sampling methods especially the Monte Carlo Simulation; generally speaking, the more samples generated, the more accurate the results and this also implies a significant amount of work and computation time. Consequently, the purpose of this paper is to compare the two sampling methods for the reliability assessment of the resistance of the composite column to flexural buckling under compression force.

GPGPU Programming for Dipolar Field Calculation

Abstract Accelerating computational processes is paramount in numerical infrastructure development, particularly in applications such as the finite element method (FEM) and extensive calculations for simulating 3D processes in materials. In this work, we introduce a novel technique for computing the magnetostatic field of an ellipsoid particle, leveraging CUDA on a graphical card for parallel processing. The implementation on a GPU resulted in a remarkable 20-fold improvement in calculation speed. This achievement not only expedites research tasks, but also enables the exploration of larger and more intricate simulations, facilitating quicker model refinements and deeper insights into material behaviours under various conditions. The utilization of GPU computing aligns with the broader trend in scientific research and engineering, offering a versatile solution for diverse computational challenges beyond this specific task of magnetism. Overall, our work contributes to the ongoing effort to harness high-performance computing (HPC) technologies for accelerated and more efficient simulations in materials science and related fields.

RESEARCH ON FRACTAL HEAT FLOW CHARACTERIZATION OF FINGER SEAL CONSIDERING THE HEAT TRANSFER EFFECT OF CONTACT GAPS ON ROUGH SURFACES

Finger seal is a new flexible dynamic sealing technology, and its heat transfer characteristics and seepage characteristics are one of the main research hotspots. In this paper, based on the fractal theory, a fractal model of the total thermal conductance of the finger seal considering the heat transfer effect of the contact gap of the rough surface is established, a fractal model of the effective gas permeability of the adjacent finger seals annulus considering the gas slip effect and the temperature change is established, and a finite element calculation method of the two-way thermo-mechanical coupling for the finger seal is proposed. The results show that the solid-phase thermal conductance decreases with the increase of the scale coefficient. When the axial pressure difference is greater than 0.4[Formula: see text]MPa, the rotor speed is greater than 11,000[Formula: see text]r/min, the radial displacement excitation is [0.03[Formula: see text]mm, 0.09[Formula: see text]mm], and the temperature is less than 600[Formula: see text]K, the gas-phase thermal conductance between the finger seal and the rotor shows an increasing trend. The gas-phase thermal conductance of the finger seal and the rotor is always the main position under different working conditions. Under different fractal dimensions, the solid-phase thermal conductance gradually occupies the dominant position. Temperature has a certain effect on the effective gas permeability, and fractal dimension, scale coefficient, and axial pressure difference have less effect on the effective gas permeability. At an axial pressure difference of 0.08[Formula: see text]MPa, the numerical calculation results of the two-way thermo-mechanical coupling calculation method for finger seal are closer to the experimental results, with a maximum error rate of 1.96%. The above results further improve the theoretical research system of the heat transfer characteristics of the finger seal.

Description of component distortion in aluminum gravity die casting as a result of hindered shrinkage and evaluation of numerical predictions

AbstractDeviation from the nominal dimension in the sense of component distortion is a quality‐reducing phenomenon in the foundry. This distortion problem as a result of impeded solidification and cooling shrinkage is of particular importance for permanent mold casting with its mechanically stiff and thermally well‐conducting molds. In studies, the temperature when the mold constraint is removed has already been identified as one of the dominant factors influencing the dimensional deviations of the casting. So far, however, no clear dependencies have been described. In the present work, the temperature up to the removal of the mold constraint is varied from near solidus to ambient temperature on a specially designed permanent mold casting made of AlSi7Mg0.3. This is compared with thermally and mechanically coupled finite elements method calculations of the investigated test geometry and the resulting component distortions. Finally, the applicability of the distortion prediction for the development of compensation strategies is evaluated.

Kaji Teoritis Pengaruh Variasi Letak Retak Terhadap Perambatan Retak Dengan Pendekatan Double Cantilever Beam (DCB)

One of the causes of structural failure is the presence of defects in the form of cracks that appear during the manufacturing or usage process of the structure. The propagation of cracks in the structure greatly depends on the value of the energy released rate possessed by the defective structure. Therefore, it is necessary to calculate the energy released rate of a structure that has a crack. One simple approach is the double cantilever beam (DCB) method. The DCB approach is derived from the change in strain energy with respect to the change in crack length. In this study, variations in crack length and crack location will be analyzed using the DCB approach and compared with the Finite Element Method (FEM) approach. It can be concluded that the calculation of strain energy can be performed using the cantilever beam approach, where the results do not significantly differ from the FEM calculations. Additionally, the strain energy is heavily influenced by the length of the beam, as longer beams result in a significant increase in strain energy (cubic relationship). The value of Energy Released Rate (ERR) is highly influenced by the crack length; a longer initial crack length leads to a quadratic increase in the Energy Released Rate (ERR). Furthermore, the value of Energy Released Rate (ERR) is also affected by the crack location; the closer the crack is to the surface of the beam, the higher the Energy Released Rate (ERR) will be.

Experimental Study on No-Load Loss Characteristics of an Alternating Current Excitation Motor

An AC excitation power supply will produce a series of harmonic currents in motors compared to the conventional power supply, increase the time harmonic component, and then generate a harmonic magnetic field; harmonics will cause motor vibrations and noise in the motor and will produce a corresponding additional loss, increasing the motor temperature rise; these key technical problems need to be solved in domestic pumped storage AC excitation motor engineering applications. Herein, the no-load loss characteristic test of a 3 MW alternating current excited motor was mainly carried out using a test prototype of the 3 MW alternating current excitation motor. Further, with the aid of the finite element method, the numerical study of the no-load loss characteristics of a 3 MW alternating current excited motor was performed. The relationship between the key factors such as the no-load characteristics, no-load loss characteristics, and constant loss and voltage per unit value is analyzed, and the variation law of the no-load core loss of motors under different loads is explored. The results demonstrate that, under no-load conditions, when the applied voltage was less than the rated voltage, the voltage was proportional to the current. When the applied voltage was more significant than the rated voltage, the current increased as the voltage increased, but the relationship between the two was no longer proportional. The constant loss of the motor maintained a linear relationship with the square of the unit value of the voltage scale. When the square of the unit value of the voltage scale was zero, the loss was equivalent to the wind friction loss under no load. The core loss increased with the increase in load, and the greater the load, the faster the increase rate of the motor iron loss. The comparison deviation between the test and simulation results was less than 10%. The simulation and experimental results verified the effectiveness of finite element modeling and the finite element calculation method.

Coupled Resonator Acoustic Waveguides‐Based Acoustic Interferometers Designed within 2D Phononic Crystals: Experiment and Theory

AbstractThe acoustic response of defect‐based acoustic interferometer‐like designs, known as Coupled Resonator Acoustic Waveguides (CRAWs), in 2D phononic crystals (PnCs) is reported. The PnC is composed of steel cylinders arranged in a square lattice within a water matrix with defects induced by selectively removing cylinders to create Mach‐Zehnder‐like (MZ) defect‐based interferometers. Two defect‐based acoustic interferometers of MZ‐type are fabricated, one with arms oriented horizontally and another one with arms oriented diagonally, and their transmission features are experimentally characterized using ultrasonic spectroscopy. The experimental data are compared with finite element method (FEM) simulations and with tight‐binding (TB) calculations in which each defect is treated as a resonator coupled to its neighboring ones. Significantly, the results exhibit excellent agreement indicating the reliability of the proposed approach. This comprehensive match is of paramount importance for accurately predicting and optimizing resonant modes supported by defect arrays, thus enabling the tailoring of phononic structures and defect‐based waveguides to meet specific requirements. This successful implementation of FEM and TB calculations in investigating CRAWs systems within PnCs paves the way for designing advanced acoustic devices with desired functionalities for various practical applications, demonstrating the application of solid‐state electronics principles to underwater acoustic devices description.

Studi Perbandingan Kekuatan Profil IWF, Hexagonal Beam dan Octagonal Beam dengan Perhitungan Manual dan Metode Elemen Hingga

A castellated beam is formed from the IWF body profile cutting pattern, and the cuts are then adjusted between the pieces and then welded to put them back together. The advantage of modifying the IWF profile into a castellated beam is that it can increase the moment of inertia of the section (Ix), and this increase affects the bending capacity of the castellated beam profile and the ability of the profile to withstand loads. However, these profile modifications have limitations that are used to minimize the occurrence of extreme failures, and one of the limitations is that the modified profile may not exceed 50% of the height increase from the initial profile height. In this study, the profile capabilities of IWF, Hexagonal Beam, and Octagonal Beam will be compared with a total of 3 models of centralized loads that can be carried. In this study, two methods will be used, namely manual calculation and finite element method. From the results of the analysis that has been carried out with both methods, it can be seen that the effect of modifying the IWF profile into hexagonal beams and octagonal beams can increase the load capacity of the profiles. However, the highest profile capability increase occurred in model 1 or IWF profile 150x75x5x7, which was modified to model 2 or hexagonal beam 220x75x5x7. The increase in the profile was 34.83% for manual method calculations and finite element method calculations, an increase of 12.15 %. The highest comparison between the manual calculation method and the finite element method occurs in the hexagonal profile beam measuring 240x75x5x7 with a difference of 21.39%. Based on the research that has been done, it can be concluded from the three profiles that it is better if the profile used is model 2.

The Interplay between Strain, Sn Content, and Temperature on Spatially Dependent Bandgap in Ge1−xSnx Microdisks

Germanium–tin (GeSn) microdisks are promising structures for complementary metal–oxide–semiconductor‐compatible lasing. Their emission properties depend on Sn concentration, strain, and operating temperature. Critically, the band structure of the alloy varies along the disk due to different lattice deformations associated with mechanical constraints. An experimental and numerical study of Ge1−x Sn x microdisk with Sn concentration between 8.5 and 14 at% is reported. Combining finite element method calculations, micro‐Raman and X‐ray diffraction spectroscopy enables a comprehensive understanding of mechanical deformation, where computational predictions are experimentally validated, leading to a robust model and insight into the strain landscape. Through micro‐photoluminescence experiments, the temperature dependence of the bandgap of Ge1−x Sn x is parametrized using the Varshni formula with respect to strain and Sn content. These results are the input for spatially dependent band structure calculations based on deformation potential theory. It is observed that Sn content and temperature have comparable effects on the bandgap, yielding a decrease of more than 20 meV for an increase of 1 at% or 100 K, respectively. The impact of the strain gradient is also analyzed. These findings correlate structural properties to emission wavelength and spectral width of microdisk lasers, thus demonstrating the importance of material‐related consideration on the design of optoelectronic microstructures.

Large-period plasmonic grating with sinusoidal profile for monitoring water quality with high sensitivity

Subwavelength-thick modulation of surface profile of a dielectric layer combined with a nanometer-thick metallic coating on it can be used for highly sensitive refractive index sensing using the concept of surface plasmon resonance. The performance efficiency of a 1D sinusoidal plasmonic grating of higher periodicity made of polymethylmethacrylate with gold coating on it is evaluated for monitoring water quality. The sinusoidal structure is fabricated by the cost-effective soft imprint lithography technique using a commercially available compact disk as master. Even though the master has a step profile, the solution-based technique aids in achieving the sinusoidal profile. The higher periodicity aids in attaining a higher sensitivity of 1533 nm/RIU at normal incidence and also provides a broad wavelength detection regime that can be controlled by the incidence angle. As the sinusoidal grating supports only the fundamental mode of the surface plasmon, it allows for more precise detection of any analyte. The optimized parameters for the structure are obtained through finite element method calculation.

How to achieve the fast computation for voxel-based irregular structures by few finite elements?

We propose machine learning (ML) based smart interpolation functions to enhance the finite element computation (named as smart-I finite element) for the heterogeneous structures (e.g., alloy material, concrete material and porous rock) that is composed of many microstructures known as voxel-based irregular shape (VI-shape). This element can directly describe the geometries with different VI-shapes and material properties without the complex meshing process by traditional finite element method (FEM). To achieve the smart interpolation in such element, a machine learning algorithm containing multiple parallel artificial neural networks (ANNs) and DeepONets assembled by the convolutional architectures is constructed for the fast prediction of interpolation functions. On this basis, the smart-I finite element is combined with classic FEM element to derive the global equilibrium equations and obtain the full-field variable distribution. Numerical tests with various material, geometrical as well as loading parameters prove that, the smart-I finite element enhanced FEM (SFEE-FEM) is able to conduct the accurate computation with a small number of elements, and thus greatly reduces the time cost. The smart-I finite element proposed by this work breaks through the limitation of traditional element shape with regular boundary (e.g., straight line), and may pave a new way to implement the FEM calculation on voxel-based geometries efficiently.

Finite Element Analysis and Calculation Method of Concrete-Filled Stainless Steel Tubes under Eccentric Tension

Concrete-filled stainless steel tubes (CFSST) could be used as structural members in corrosion-prone environments. A detailed numerical investigation of the mechanical performance and calculation method of CFSST members under eccentric tension is carried out in this paper. A finite element analysis (FEA) model that adopts three-dimensional elements is established, and related experimental results of CFSST and conventional concrete-filled carbon steel tubes (CFST) subjected to tension are used to validate the FEA model. Then, the calibrated FEA model is used to investigate the performance of CFSST eccentrically tensile members, especially the composite actions and stress distribution laws between the stainless steel tube and the concrete core, which play a key role in the load-carrying capacity of the composite member. To quantitatively determine the influence of different parameters on the load-carrying capacity of CFSST tensile members, a wide-range parametric analysis is performed. Finally, a calculation model is proposed to be used to predict the ultimate tensile strength of CFSST members subjected to eccentric tension, and the model-predicted values show good agreement with the FEA-computed results.