ANSYS APDL Research Articles

Comparative Study of Core Material's Stiffness on Sandwich Panel with Composite Face Sheets beyond the Yield Point

The study aims to explore the performance of sandwich panels exceeding the yield point stiffness of the core material. Sandwich panels have gained growing attention among designers owing to their excellent corrosion properties, and lightweight, and speedy installation process. They have been applied in numerous industrial sectors, including aerospace, architectural, marine, and transportation. Typically, sandwich panels are composed of a single central core sandwiched by a pair of outer face sheets, where the core is normally developed using softer materials compared to the face sheets. Given that past studies have primarily focused on sandwich panels in the elastic range, this present study explored the performance of sandwich panels exceeding the yield point stiffness of the core material. The univariate search optimization method was utilized to assess the elastic modulus ratio of the core (typically foam) to the face sheet (composite material). The load was elevated in a quasi-static order until the face sheets reached their yield point. Subsequently, the panel was simulated using the finite element analysis commercial package ANSYS APDL, with simply supported boundary conditions used on all sides of the panel. The proposed model was verified by comparing the numerical and experimental data from recent literature. Based on the results, the panel's increased load-carrying capacity corresponded as the core material stiffness exceeded its yield limit. Moreover, the transmission of load to the face sheets increased as the core stiffness decreased. In summary, stiffer core materials caused the sandwich panel to behave more as isotopic face sheets. Thus, the face sheets yielded ahead of the core material.

Analysis and Optimization of Laser Beam Welding Parameters for Aluminium Composite (Al-Zn-Cu Alloy) by Grey Relational Optimization

Aluminium and its composites are widely used in production to enhance the strength of lightweight objects. In this study, an AA7075/SiC composite was fabricated using a stir casting route. Multi-objective optimization and finite element analysis were performed with various process parameters on a manufactured aluminium composite (AA7075 + SiC) undergoing a laser beam welding process. Four welding parameters, i.e., pulse frequency, power, welding speed (transverse), and wire size were taken for laser welding as per the L-9 orthogonal array for experimental study. Tensile strength, deflection, temperature distribution, Rockwell hardness (fusion zone), and Rockwell hardness (heat affected zone) were taken as output parameters after welding. The standard deviation objective weighting–grey relational optimization method optimized the process parameter. ANSYS APDL 23 software was utilized to simulate the entire laser welding method with a cylindrical heat source to predict the temperature distribution in the butt-welded plates. This software uses finite element analysis and gives a deviation of only 5.85% for temperature distribution with experimental results. This study helps to understand the effect of various parameters on the welding strength of the aluminium composite.

Fatigue life prediction of BGA solder joint of several alloy compositions under an isothermal harmonic vibration

To ensure durable performance and optimal function of electronic components, it is crucial to guarantee their reliability, robustness and goodness of fit. The solder joints used in the BGA (Ball Grid Array) component play an intrinsic role in the reliability of the system. The vibration present in BGA triggers fatigue in solder joints, which raises a major reliability problem in various sectors such as aerospace, automotive and military industries. This study handles the response to a harmonic vibration at three specific temperatures (−40°C, 25°C, and 125°C) for four types of solder alloys in BGA Soldering. Within this framework, predicting the fatigue life of BGA solder joints with various alloy compositions under the influence of an isothermal harmonic vibration emerges as a crucial challenge in the design as well as reliability of modern electronic devices. The investigated solder compositions are SAC105, SAC305, SAC405, and InnoLot. To simulate and analyze the behavior of solder joints, we used the Ansys APDL finite element analysis (FEA). At both 125°C and −40°C, the Von Mises values proved to exceed those observed at 25°C. Likewise, an S-N curve for InnoLot and the different SACs, under a harmonic vibration at 25°C, was fitted using the Basquin power law relationship. As far as the current research work is concerned, an initial comparison was enacted between InnoLot and SAC alloys under an isothermal harmonic vibration, aiming to ascertain the most reliable alloy. The fatigue life under a harmonic vibration loading at 25°C was estimated. The results revealed that under a harmonic vibration at 25°C, the InnoLot solder displayed the longest lifespan, while the SAC105 solder exhibited the shortest fatigue life.

Developing Programs for Converting MIDAS GEN to ANSYS Models Based on Python

The reasonableness and accuracy of engineering design are often assessed through the use of a variety of structural design analysis software, which are then compared and verified. However, it is challenging for a single analysis software to meet the diverse and complex design requirements. In order to meet the specific engineering requirements, it is necessary to convert the MIDAS result model into an ANSYS structural model and conduct a nonlinear analysis and simulation in ANSYS. Nevertheless, the existing interface is unable to facilitate direct conversion of the model. Accordingly, this paper presents a Python-based ANSYS APDL program that enables the complete conversion of MIDAS GEN structural models to ANSYS finite element models. The program is capable of converting a range of data, including material, section, element, connection, load, node mass, constraint, time history function, and so forth. The program is capable of converting specific connection units, including elastic and general connection units. Additionally, the beam-column section direction, beam end freedom release, rigid element, and special anti-rocking structure of the structure can be considered. Ultimately, the theatre model is transformed. Following a comparison of the analysis results, it was found that the mass and mode of the model before and after the transformation were essentially identical. The maximum error of the first six orders of the structure is 2.95%, with the structural displacement under gravity load remaining essentially unchanged. The research and analysis demonstrate the accuracy and reliability of the MIDAS GEN conversion ANSYS program. The conversion program significantly reduces the time required for direct modeling in ANSYS, enhancing work efficiency. The study has considerable practical significance for the seismic sway design and analysis of buildings based on vibration isolation design.

Design of a tooth-shaped magnetorheological brake with multiple coils

This research presents an optimized design for a tooth-shaped magnetorheological brake (MRB) with multiple coils. The MRB configuration consists of a disk immersed in magnetorheological fluid (MRF), where four coils act as electromagnets when an electric current is applied. The energized coils induce the alignment of suspended particles in the MRF, forming a chain-like structure that increases the fluid's viscosity. This rapid, strong, and controllable phenomenon enables the MRB to find applications in haptic systems, tension control, and industrial braking systems. To analyze the electromagnetic behavior of the brake, Finite Element Method (FEM) simulations are conducted using ANSYS APDL, and the optimization process is performed utilizing ANSYS Workbench software. The software provides optimized geometries for the brake, resulting in significant improvements in desired performance aspects compared to prior designs, etc.

A new optimization framework for piezoelectric actuators location identification

The study addresses piezoelectric actuator placement for active vibration control using an open-access framework that couples ANSYS and Python. It outlines a three-stage procedure: creating a finite element model in ANSYS APDL, using Python to determine the objective function, and applying a genetic algorithm optimization to find optimal actuator locations. Numerical simulations on plates and thin-walled conical structures demonstrate the effectiveness of the approach, showing it efficiently finds optimal placements with minimal search time and energy requirements. The study provides open-access codes for the framework, enhancing its accessibility and reproducibility.

Determination of Dynamic Stresses and Displacements under the Action of an Impact Load on a Two-Layer Structure during the Indentation Process

Introduction. Numerous researchers of the reliability of building structures pay attention to hardness, an important characteristic of the structural material. It is determined by indentation — pressing the tip of the tool into the surface. The advantages of dynamic indentation methods and the distribution of stress intensity on the surface and inside the sample are investigated. However, the condition of layered materials on impact has been poorly studied. The objective of the presented work is to consider indentation for a two-layer sample and determine the sensitivity of the top layer to the strength of the substrate. This will allow us to identify significant characteristics of the strength properties of homogeneous and heterogeneous structures.Materials and Methods. An elastoplastic model of material behavior and a shock indentation scheme were used, which took into account the masses of the indenter and the striker coupled by linear springs. The surface of the indenter was conical, the opening angle was 120°. The impact was simulated in the MATLAB system. Finite element model in Ansys APDL was used to verify the data and analyze the results of the experiment. Traditional models of elasticity theory were used for calculations. The behavior of the material in the zone of plastic deformation was described using the options of multilinear isotropic hardening and the von Mises plasticity criterion.Results. The results of comparing three versions of varying the level of yield strength in the bottom layer are presented: when the yield strength in the bottom layer is half as high as the top one, equal to it, and twice as high. Displacements at different observation points for samples with a top layer of 2 mm and 1 mm were analyzed. In the first case, under horizontal shear, the displacement indices inside the sample did not change if the yield strength level was twice lower or higher than in the top one. If these indicators were equal, the difference became noticeable. In the second case (layer 1 mm), the difference in displacement was visible at all observation points. Thus, it can be reasonably concluded that a structure with a smaller top layer is more sensitive to impact. In the course of the research, it became known that vibrations associated with the transition to the plasticity zone occurred in the 2 mm zone, and elastic damping vibrations occurred below this zone. We solved the classification problem for the top layer of the material with changing characteristics of the base. The indicator for comparison was the Brinell hardness (HB) in the range of 200–600. The results were processed using a neural network and visualized in the form of graphs. The accuracy of its calculations was 98%.Discussion and Conclusion. To determine the strength properties of homogeneous structures, it is sufficient to characterize the speed of displacement inside the sample. For an inhomogeneous structure, additional parameters should be introduced — displacements on the surface and inside the sample at fixed observation points. An integrated approach to determining the strength properties of an inhomogeneous structure improves the accuracy of calculations, and the use of neural networks increases their speed.

Study of Design and Analysis of S-glass Fiber Reinforced Epoxy Polymer Metal Laminate Composites in the Application of Propeller Shafts

The propeller shafts are utilized to transmit power from gear box to rear wheels in automobiles. It is found that the weight, cost, critical speed and buckling of shafts are the serious issues in conventional metallic propeller shafts. The propeller shafts made up of composite material are best suited for LMV due to single piece manufacturing. The fiber metal laminate propeller shafts are getting popular as the metal liner adds extra strength, rigidity and acts as a substrate and avoids leaking during manufacturing. The propeller shaft of light motor vehicle was selected for study. S-glass fibers, epoxy and a thin mild steel liner are the materials chosen. The design of the shaft was carried out according to ASME Standard code of design. The ply orientation and stacking sequence are selected as [±45°, 0°, 90°], to increase the torsional strength, enhance natural frequency and buckling strength respectively. The finite element analysis of the propeller shaft is carried out in Ansys APDL. It is found from the analysis that the weight, torsional strength, torsional stiffness and natural frequency of the S-glass fiber reinforced Epoxy Metal Laminate (FML) composites are superior than the conventional C-35 alloy steel material, and hence can be an alternative to the conventional alloy steel shaft.

Numerical simulation of contact surface stress distribution based on stress-magnetization effect surface

Taking the surface profile of C45 steel grinding as the research object, a two-dimensional finite element contact model of rough surface and smooth rigid surface was established by using ANSYS software, and the stress distribution characteristics and rules of contact surface were analyzed under 0–10 MPa normal load. On this basis, the force-magnetic coupling model was established by using ANSYS APDL language. Furthermore, the influence of stress under on leakage magnetic field of contact surface under different load conditions was studied. The results indicated that according to the zero-crossing point of the normal component of the leakage magnetic field or the extreme point of the tangential component, the number of stress concentrations on the contact surface and the stress level of the corresponding area can be effectively determined. This innovative approach offers valuable insights for future studies on surface contact stress distribution between components.

Experimental and numerical modal analysis of CFM56-3 Oil tank

To determine the dynamic behavior of components which is performed through the mechanical vibration analysis. The Experimental Modal Analysis (EMA) is the process to determine the modal parameters i.e. of natural frequencies, mode shapes, and damping. The Experimental Modal Analysis (EMA) of the CFM56 oil tank was performed using an impact hammer and a laser vibrometer. Finite Element Modeling (FEM) software, ANSYS APDL 19.2, was used to performed numerical modal analysis of the same oil tank. Thus, the results obtained for natural frequencies and mode shapes is presented in this document. It will contribute to the demonstration of the component functionality and to the validation of the proposed analysis methodology.

Research on Macroscopic Mechanical Behavior of Recycled Aggregate Concrete Based on Mesoscale.

Recycled concrete is a heterogeneous composite material, and the composition and volume fraction of each phase affect its macroscopic properties. In this paper, ANSYS APDL was used to construct a two-dimensional numerical model of recycled aggregate concrete with different replacement rates of recycled aggregate (0%, 25%, 50%, 75% and 100%), and a uniaxial compression test was carried out to explore the relationship between recycled aggregate content and its macroscopic mechanical behavior. On this basis, the numerical simulation of different strain rates (0.1 s-1, 0.05 s-1, 0.01 s-1, 0.005 s-1 and 0.001 s-1) was carried out. It was found that with the increase in the recycled aggregate replacement rate, the peak stress decreases first and then increases, and the peak strain increases continuously. When the replacement rate of recycled aggregate exceeds 50%, the overall damage area of the material increases rapidly. The strain rate will change the path of the micro-crack initiation and expansion of recycled concrete, as well as the process of damage accumulation and evolution. As a result, the unit area and shape of recycled concrete are different at different strain rates, and the damage degree of each phase material is also different.

A Numerical Model to Predict the Relaxation Phenomena in Thermoset Polymers and Their Effects on Residual Stress during Curing-Part I: A Theoretical Formulation and Numerical Evaluation of Relaxation Phenomena.

This paper analyzes the effect of crosslinking reactions on a thermoset polymer's viscoelastic properties. In particular, a numerical model to predict the evolution of epoxy's mechanical properties during the curing process is proposed and implemented in an Ansys APDL environment. A linear viscoelastic behavior is assumed, and the scaling of viscoelastic properties in terms of the temperature and degree of conversion is modeled using a modified version of the TNM (Tool-Narayanaswamy-Mohynian) model. The effects of the degree of conversion and structural relaxation on epoxy's relaxation times are simultaneously examined for the first time. This formulation is based on the thermo-rheological and chemo-rheological simplicities hypothesis and can predict the evolution of epoxy's relaxation phenomena. The thermal-kinetic reactions of curing are implemented in a homemade routine written in APDL language, and the structural module of Ansys is used to predict the polymer's creep and stress relaxation curves at different temperatures and degrees of conversion.

Finite element analysis of self-tensioning and bursting of 210 L carbon fiber fully wound hydrogen storage cylinders

This paper focuses on a 210 L carbon fiber fully wound hydrogen storage cylinder. A 1/8 scale model is selected for analysis. Using the finite element software ANSYS APDL and secondary development language, an orthotropic material performance equation is formulated and applied to the composite material lay-up. Following DOT CFFC standards, the cylinder undergoes simulated loading and unloading analysis to determine the optimal self-tightening pressure. Subsequently, progressive failure theory and the Tsai-Wu failure criterion are employed to identify the failure modes of the composite material. Continual adjustments to the element stiffness are made during the loading process. Employing the element birth and death technique, failed elements are terminated and recorded, and based on increasing trends, the burst pressure of the cylinder can be predicted. The results closely align with experimental data, validating its applicability as the basis for burst prediction.

Studying the Effect of Elastoviscoplastic Modeling on Burst Speed Margins of Turbine Disc

Abstract: Aero engine turbine discs are critical components that can shatter owing to excessive mechanical loads during operation, endangering aircraft safety. Understanding burst speed margins, the buffer between maximum and actual rotational speeds, is essential for ensuring safety. ANSYS APDL software is used to examine a 2D axisymmetric non-uniform turbine disc utilizing INCONEL 718 and Ti-6Al-4V materials and numerous models. This research, which includes centrifugal, gas, and thermal loads, accurately predicts burst speed and confirms linear elastic analysis. For elastic-plastic analysis, Robinson's criterion is utilized, Perzyna for elastoviscoplastic behavior, and Bilinear isotropic hardening for elastic-plastic behavior. A sensitivity analysis of Perzyna model parameters reveals that elastoviscoplastic analysis yields higher burst margins than elasticplastic analysis for this turbine disc. The parameters are calibrated using existing models from the Literature.

Theoretical and Finite Element Analysis of Pressure Vessel

Objectives: This study tests the vessel strength and performance of pressure vessel under Internal pressure, Nozzle loads, and Hydro-test using Ansys APDL, validating design alignment with ASME Section VIII following the Design by rule (Analytical) and Design by Analysis (FEA) accurate elastic analysis approach. Methods: This study employs ASME methods to validate vessel integrity under various loads. Strength is confirmed through analytical formulas and Finite Element Analysis (FEA) using ANSYS APDL, aligned with widely used ASME BPVC codes in the oil and gas industry. The FE model, utilizing hex elements, ensures result accuracy with a minimum of three elements across thickness. Boundary conditions are validated by comparing hoop stress in FEA with analytically calculated values. ASME's computationally efficient elastic analysis, employing a linear approach, includes stress linearization at discontinuity and non-discontinuity locations, verifying vessel design through analysis. Findings: Initial thicknesses for the shell and cone exceeded analytically calculated minimums, affirming vessel structural integrity through ASME's design by rule approach. Finite Element Analysis (FEA) stress analysis at critical points, such as nozzle junctions and other discontinuity areas, validates accuracy through hoop stress checks. Analysis of design and test load cases reveals stress categories well within ASME Sec VIII limits, confirming the vessel's safety and compliance with elastic stress analysis standards. Novelty: This method emerges as a reliable tool for vessel design, ensuring safety and ASME compliance, particularly beneficial for industries like oil and gas. It provides precise guidelines utilizing hex mesh, validates boundary conditions through hoop stress comparison, and comprehensively assesses stress in critical and non-critical zones through elastic stress analysis. Addressing common challenges identified in the literature review, this approach enhances the accuracy and reliability of pressure vessel designs in compliance with ASME standards for design and test loadings. Keywords: Pressure Vessels, Process Industries, Stress, Loads, Pressure, Thermal, Design Validation, ASME, FE analysis

Vehicle load identification based on bridge response using deep convolutional neural network

ABSTRACT Ensuring bridge safety and longevity through precise vehicle load characterization is crucial for maintaining structural integrity and efficiency. This research highlights the efficacy of deep convolutional neural networks (DCNNs) in analyzing bridge responses. The proposed methodology incorporates abridge model developed in ANSYS APDL, integrated subsequently with Universal Mechanism (UM) software for simulating vehicle-bridge interactions, considering factors such as vehicle load, speed, road surface roughness, and ambient noise. To validate the accuracy and robustness of the DCNN models, the study involved training and testing them on diverse datasets, each comprising 250 randomized samples for various parameters such as load, speed, and surface roughness. Two popular deep learning frameworks, ResNet and Inception models, were employed to assess their capability to identify these critical vehicle-bridge interaction characteristics accurately. The results reveal that the Inception model excelled in vehicle load identification, achieving an impressive validation accuracy of 99.9%. In contrast, ResNet outperformed in vehicle speed identification with a99% validation accuracy, surpassing Inception’s 97.9%. Both models exhibited remarkable resilience to noise, with road surface roughness identification demonstrating exceptional performance, including aperfect 100% training accuracy for ResNet and 99.9% for Inception. Furthermore, to validate the noise robustness of the DCNN model, the load identification is conducted under the effects of measurement noise, and the identification results show that the DCNN model can accurately identify vehicle loads with accuracies of 97.9% at 10 dB and 99.7% at 20 dB, respectively. These findings firmly establish the DCNNs’ capability to accurately identify vehicle load, speed, and road surface roughness, emphasizing their potential to significantly improve bridge safety and longevity.

Design and empirical evaluation of a magneto-rheological fluid-based seal with rectangular and trapezoidal pole head

The focus of this study is on the design and experimental validation of MRF self-sealing (also known as MRF seal) utilizing permanent magnets. The MRF seal has been built to readily replace traditional seal (lip-seal) for rotation shaft sealing. Following a review of studies on MRF seals, two configurations of MRF seal featuring an axial permanent magnet and two distinct pole head forms, rectangular and trapezoidal, are presented. The two MRF seals are then subjected to a magnetic analysis using the finite element method (ANSYS APDL). The Bingham plastic model of MRF and the assumption of linear velocity profile of MRF in the sealing gap are employed to construct mathematical models of crucial seal characteristics such as maximum static working pressure and frictional torque. The seals are optimized employing the optimization toolbox integrated in the ANSYS APDL to obtain the optimal geometric dimensions of the MRF seals. Finally, prototypes of the two MRF seals are fabricated and testing work is conducted to validate and compare them with the simulated results.

Vibration Analysis of Damaged Viscoelastic Composite Sandwich Plate

This paper presents a study of free and forced vibration of composite sandwich plate with and without damage using the finite element analysis developed under ANSYS APDL software. This modeling uses the 8-node shell 281 element to modelized the composite laminates of the top and bottom face sheets of the sandwich plate and the 20-node higher order solid 186 element to modelized the viscoelastic core. Two sets of boundaries are considered; Simply supported and clamped boundary conditions at all edges. The effect of damaged face sheets layers on natural frequencies, mode shapes, the frequency and transient responses of the sandwich plate is investigated. Numerical results show remarkable shifts of the natural frequencies, frequency and transient responses due to the presence of damage. It is concluded that the natural frequencies decreasing is due to the loss of structural stiffness. Natural frequencies of the sandwich plates are close to those issued from numerical results available in the literature.

Optimization of Structural Steel Used in Concrete-Encased Steel Composite Columns via Topology Optimization

Concrete-encased steel composite columns are preferred for their exceptional ductility and strength, particularly in high-rise buildings. This research aims to enhance both the strength and ductility of these composite columns by increasing the height of the steel profile. Typically, hexagonal or circular openings, referred to as castellated elements, are incorporated into the steel profile to achieve this height increase. This study employed a topology optimization method to identify the ideal opening shape for the steel profile in concrete-encased steel composite columns. The analysis revealed a sinusoidal-like opening shape, which was then refined for manufacturing. The optimal opening shape was used to increase the height of the existing steel profile, and nonlinear analyses were conducted to evaluate the effectiveness of this new optimized steel profile in concrete-encased steel composite columns. Two concrete-encased steel composite columns were designed: one with the optimal steel profile and the other with a standard steel I profile. ANSYS APDL 19.0 software was used to simulate an experiment based on an existing concrete-encased steel column to validate the nonlinear analysis. The verification analysis demonstrated a remarkable similarity between the experimental and numerical load–displacement graphs, indicating that the numerical analysis was reliable. In the analysis of the composite columns, both axial and lateral forces were applied in the nonlinear analyses. The axial force was applied at 15% of the column’s capacity, while the lateral force was applied until the composite column reached a state of failure. The results of the nonlinear analyses allowed for a comparison of load–displacement curves and the performance of the composite columns. In comparison to the standard steel I profile, the steel profile with the optimal opening shape increased load-carrying capacity by approximately 19% and energy absorption capacity by approximately 24%.

Analysis of Brush Seal Interaction with Steam Turbine Rotor-Shafts

High-speed turbines are a major source for power production. They utilize high pressure and temperature fluid flow. Sealing of these machines to decrease the flow losses has been a major engineering challenge since the inception of steam turbines. From an engineering viewpoint, seals are used to introduce friction in the fluid flow path. This reduces the flow leakage. Improved seal performance offers substantial opportunities for turbine performance. Reduced leakages in steam turbines can lead to greater efficiency and power output. They can also allow tighter control of turbine secondary flows. However, sealing these machines is a major challenge. There are several seal locations on a steam turbine that have significant performance derivatives. These include the interstage shaft packing, the end packing, and the bucket tip seals. Brush seals are ideal for these locations because they can reduce the flow losses. This study analysed the efficiency of the steam turbine by using ANSYS APDL. It assessed the leakage performance of the brush seal for different cases and geometries. It also used porous medium modelling of the bristle pack to provide insight for designers. The outputs of interest were the rotor-shaft temperature and the efficiency of the entire turbine with the brush seal.