ABAQUS Model Research Articles

Correlation analysis between coiling tension and the sleeve's hoop stress

The coiling process, crucial for winding long sheets of consistent thickness, often encounters challenges due to deformation induced by pressure and frictional forces on the inner mandrel and sleeve. This necessitates precise stress calculations to ensure operational safety within elastic deformation limits. This study proposes a novel mathematical model to accurately predict stress distribution in the sleeve's hoop direction. The mathematical model is modified by applying a correction factor, derived from an enhanced analytical solution based on the Lame equation, specifically tailored to address coiling stress during prior elastic deformation. Validation of the proposed analytical solution was carried out using finite element analysis through the ABAQUS model. This validation process revealed variations in stress within the sleeve's hoop direction corresponding to different coiling tensions. Furthermore, parametric analysis highlighted a correlation between increased coiling tension and higher frictional forces exerted by the first layer of the steel coil on the sleeve, resulting in discernible variations in hoop stress based on sleeve radius and coiling tension. The key innovation lies in the application of the correction factor to the Lame equation, enabling the derivation of stress results consistent with finite element analysis, even under arbitrary coiling tension and sleeve radius inputs. This analytical solution not only holds promise for predicting the behavior of various thick-walled cylinders produced through different manufacturing processes involving coiling but also facilitates integration with monitoring systems to mitigate slumping during steel rolling operations, all while minimizing computational burden.

The reduction of stress concentrations in adhesive joints with the use of curved aluminum adherends

The study proposes a novel concept of a curved single lap joint (SLJ) with non- uniform adhesive thickness to reduce stress concentrations near overlap edges. Experimental and numerical methodologies investigate this joint using two adhesives: Araldite 2015-1 and AV138. Numerical models in ABAQUS predict cohesive failure in the adhesive layer. The curved configuration doesn’t significantly enhance strength in SLJ using ductile adhesives, but for brittle ones, strength increased by 131% due to sensitivity to peak stresses. In conclusion, the curved SLJ effectively reduces stress concentrations and the effectiveness of this concept is linked to the ductility of the adhesive used.

The Analysis of the Fracturing Mechanism and Brittleness Characteristics of Anisotropic Shale Based on Finite-Discrete Element Method

AbstractShale anisotropy characteristics have great effects on the mechanical behaviour of the rock. Understanding shale anisotropic behaviour is one of the key interests to several geo-engineering fields, including tunnel, nuclear waste disposal and hydraulic fracturing. This research adopted the finite discrete element method (FDEM) to create anisotropic shale models in ABAQUS. The FDEM models were calibrated using the mechanical values obtained from published laboratory tests on Longmaxi shale. The results show that the anisotropic features of shale significantly affect the brittleness and fracturing mechanism at the micro-crack level. The total fracture number in shale under the Uniaxial Compressive Strength (UCS) test is not only related to the brittleness of shale. It is also strongly dependent on the structure of the shale, which is sensitive to shale anisotropy. Two new brittleness indices, BIf and BICD, have been proposed in this paper. The expression for BIf directly incorporates the number of fractures formed inside of the rock, which provides a more accurate frac-ability using this brittleness index. It can be used to calculate the frac-ability of rocks in projects where there are concerns about fractures after excavation. Meanwhile, BICD links brittleness to the CD/UCS ratio in shale for the first time. BICD is easy to obtain in comparison to other brittleness indices because it is based on the Uniaxial Compressive Strength test only. In addition, it has been shown there is a relationship between tensile strength and the crack damage strength in shale. Based on this, an empirical relationship has been proposed to predict the tensile strength based on the Uniaxial Compressive Strength test.

Identification of Vivo Material Parameters of Arterial Wall Based on Improved Niching Genetic Algorithm and Neural Networks

Cardiovascular diseases are seriously threatening human health and the incidence rate is high. Many scholars are devoted to studying arterial mechanical properties and material parameters. In this study, the bovine artery was selected as the experimental object and the uniaxial tensile test was carried out by cutting the specimens along its axial, circumferential and [Formula: see text] directions. The finite element software ABAQUS and hyperelastic Holzapfel Gasser Ogden (HGO) constitutive model were used to simulate the experimental process. Niche technology is introduced on the basis of genetic algorithm, and the program of Improved Niche Genetic Algorithm for material parameter identification is compiled based on Python language. In addition, BP Neural Network was constructed based on Tensorflow mathematical system. The material parameters of the constitutive model of bovine artery in different directions were identified by finite element method and experimental data. The results show that Improved Niche Genetic Algorithm and Neural Network, respectively, combined with finite element are both effective and accurate methods for predicting the parameters of arterial vascular hyperelastic materials, which can provide reference and help for the study of arterial vascular mechanical properties.

Calibrating DC01 Material Properties for Finite Element Analysis with Abaqus and Isight

Abstract This article explores the process of calibrating the properties of DC01 materials for finite element analysis using ABAQUS and Isight. Precise calibration of yield strength and tensile strength is crucial for accurately modeling material behavior under various loading conditions. The article details the sample preparation process, deformation measurements, and tensile tests to obtain experimental data. These data are then used to calibrate the DC01 material model in ABAQUS with the assistance of Isight, ensuring that the simulations accurately reflect real-world behavior. The results indicate the success of the calibration, facilitating the design and testing of products in a predictive virtual environment. Precise calibration is essential for predicting material behavior in real-world conditions and minimizing the risk of implementation failures.

Inhomogeneous thermal analysis of microlayer mold for glass molding of fast-axis collimation lens array

Fast-axis collimation (FAC) lens arrays play a crucial role in laser systems, offering precise beam shaping and focusing for applications such as laser marking, and optical communication. Achieving high precision in these applications requires a FAC lens array with a long Rayleigh range. While precision glass molding with nickel-phosphorus (Ni-P) microlayer molds has revolutionized the mass production of FAC lens arrays, the extreme conditions during the molding process can lead to poor profile accuracy. To address this issue, we developed an optical collimation system to derive the final characteristic parameters and obtain the beam waist radius and Rayleigh range of the collimated laser. Additionally, we conducted a thorough analysis of the inhomogeneous thermal expansion process of the microlayer mold and established a mathematical solution for thermal compensation to modify the mold's shape. We validated the proposed method by fabricating an FAC lens array mold and measuring the profile error and waist radius of a molded FAC lens array. We also calculated the profile error of this method using a finite element (FE) model in ABAQUS. The results indicate that incorporating the inhomogeneous thermal expansion reduces the shape error of the FAC lens array from 0.577 μm to 0.135 μm. Moreover, using inhomogeneous thermal compensation significantly improves the Rayleigh range of the FAC lens array from 1.285 μm to 9.8 × 104 μm.

Dynamic Response of Transmission Tower-Line Systems Due to Ground Vibration Caused by High-Speed Trains

With the continuous expansion of the scale of power grid and transportation infrastructure construction, the number of crossovers between transmission lines and high-speed railways continues to increase. At present, there is a lack of systematic research on the dynamic characteristics of transmission tower-line structures crossing high-speed railways under vehicle-induced ground vibration. This article focuses on the phenomenon of accidents such as line drops when crossing areas in recent years and establishes a high-speed train track foundation soil finite element model in ABAQUS that considers track irregularity. The three-dimensional vibration characteristics and attenuation law of train ground vibration are analyzed. Acceleration data for key points are also extracted. A separate finite element model of the transmission tower-line system is established in ANSYS, where acceleration is applied as an excitation to the transmission tower-line system, and the coupling effect between the tower and the line is considered to analyze its dynamic response. Subsequently, modal analysis is conducted on the tower-line system, providing the vibration modes and natural frequencies of the transmission tower-line structure. The effects of factors such as train speed, soil quality, and distance from the tower to the track on the dynamic response of the transmission tower-line system under vehicle-induced ground vibration are studied. The results show that the speed range (300 km/h–400 km/h) and track distance range (4.5 m–30 m) with the greatest impacts are obtained. The research results can provide a reference for the reasonable design of transmission tower-line systems in high-speed railway sections.

Numerical modeling on the deformation features of expansive soil slopes under moisture variations based on Fractal model

Expansive soils exhibit significant swelling-shrinkage characteristic under the cyclic moisture changes. The expansive soil slopes with high designing safety factor (gentle slope and low rainfall level) will also fail, which could not happen in an analysis ignoring expansive deformations. In this paper, the basic pore surface fractal model is derived and user-defined subroutines performing swelling-shrinkage deformation are developed to simulate the deformation features of expansive soil slopes under moisture variations. First, Fractal model is verified experimentally for accuracy in describing expansive soil issues. A hydro-mechanical coupling model based on the Fractal model in ABAQUS is then established to enable the numerical analysis of expansive soil slopes. In addition, the effects of swelling deformation, desiccation and slope ratio on deformation features are investigated. The results show that the consideration of swelling-shrinkage deformation causes the slope deformation features change, promotes larger additional displacements, and enhances water sensitivity. The simulated slopes can exhibit typical gentle sliding, shallow and progressive damage after several moisture cycling. This research provides a design reference for expansive soil slopes and expansive soil associated catastrophic issues.

Simulation of temperature and weld growth mechanism in ultrasonic welding of carbon fiber reinforced polyamide 66 composite: Employing the high frequency real-time horn vibration

Ultrasonic welding (UW) of carbon fiber reinforced polyamide 66 (CF/PA 66) composite is a very promising process for assembly of automobile component. Simulation of the temperature distribution and weld growth in UW process remains a difficulty issue. In this study, a high frequency sensor is equipped in the welder to collect the real-time horn vibration during UW. Then the real-time horn vibration is applied on tip of the horn and integrated into the finite element model in Abaqus. The simulation results are validated with experimental tests of temperature and weld evolution in UW of CF/PA 66. Results showed the ultrasonically welded CF/PA 66 joint made with a weld time of 2.7 s consisted of five distinct stages and the characteristics in stage 3 determined the quality of the weld. An index Q based on the amplitude and duration of T3 was proposed to evaluate the joint quality. The accuracy of Q was also verified through extensive experiments.

Study on vehicle-bridge coupling vibration response and impact factor of spatial Y-shaped tied arch bridge

The spatial Y-shaped steel arch bridge adopts a single and double arch rib composite structure, which has a complex spatial structure, and its structural dynamic characteristics are special, resulting in a more complex vehicle-bridge coupling vibration response law. To clarify the dynamic characteristics of the space Y-shaped steel arch bridge structure, this paper takes a space Y-shaped steel arch bridge under construction in China as the research object and uses ABAQUS to establish a vehicle-bridge coupling model. The correctness of the ABAQUS model is verified by the bridge model established by Midas Civil, and four grades of road roughness are established by using the ABAQUS kernel command. The influence of vehicle speed and road roughness on the spatial Y-shaped steel arch bridge is analyzed. The impact factor of the vehicle on the flat bridge deck at the design speed is calculated and compared with the current specification, which provides a reference for the design and maintenance of space Y-shaped steel arch bridge in the future.

A novel computer modeling and simulation technique for bronchi motion tracking in human lungs under respiration

In this work, we proposed a novel computer modeling and simulation technique for motion tracking of lung bronchi (or tumors) under respiration using 9 cases of computed tomography (CT)-based patient-specific finite element (FE) models and Ogden’s hyperelastic model. In the fabrication of patient-specific FE models for the respiratory system, various organs such as the mediastinum, diaphragm, and thorax that could affect the lung motions during breathing were considered. To describe the nonlinear material behavior of lung parenchyma, the comparative simulation for biaxial tension-compression of lung parenchyma was carried out using several hyperelastic models in ABAQUS, and then, Ogden’s model was adopted as an optimal model. Based on the aforementioned FE models and Ogden’s material model, the 9 cases of respiration simulation were carried out from exhalation to inhalation, and the motion of lung bronchi (or tumors) was tracked. In addition, the changes in lung volume, lung cross-sectional area on the axial plane during breathing were calculated. Finally, the simulation results were quantitatively compared to the inhalation/exhalation CT images of 9 subjects to validate the proposed technique. Through the simulation, it was confirmed that the average relative errors of simulation to clinical data regarding to the displacement of 258 landmarks in the lung bronchi branches of total subjects were 1.10%~2.67%. In addition, the average relative errors of those with respect to the lung cross-sectional area changes and the volume changes in the superior-inferior direction were 0.20%~5.00% and 1.29 ~ 9.23%, respectively. Hence, it was considered that the simulation results were coincided well with the clinical data. The novelty of the present study is as follows: (1) The framework from fabrication of the human respiratory system to validation of the bronchi motion tracking is provided step by step. (2) The comparative simulation study for nonlinear material behavior of lung parenchyma was carried out to describe the realistic lung motion. (3) Various organs surrounding the lung parenchyma and restricting its motion were considered in respiration simulation. (4) The simulation results such as landmark displacement, lung cross-sectional area/volume changes were quantitatively compared to the clinical data of 9 subjects.

Prediction of FLD using Abaqus and Gurson Model for Simple Flat Spacemen

In the past century, in many industries, such as, metal forming industry, it has been important to predict ductile damage and fracture of metals under complex loadings. Regarding damage mechanics, one of the most classical models is the GTN, which was originated from Gurson and later enhanced by Tvergaard and Needleman. The inprovement was achieved by introducing an equivalent void volume fraction f and two more parameters called q1 and q2 into the yield function of Gurson’s model.

Structural behavior of UHPC epoxy composite plate subjected to velocity impact loading

This article aims to investigate the structural behavior of Ultra High Performance Epoxy Composite Plate subjected to velocity impact loading. Two types of material were utilized for the composite plate: epoxy, and UHPC. UHPC plate plays as a front layer to strengthen the energy absorption and protect the epoxy layer. The material model used to simulate the epoxy plate was verified by experimental results to prove its accuracy and efficiency. Impact loading was implemented in the Abaqus model by an impactor nose which has 25mm diameter. The projectile was assumed at the velocity of 120 m/s. The damage propagated due to the increment of the impact energy was estimated by the Johnson-Holmsquist concrete (JHC) material model in Abaqus. Maximum deflection, the kinetic energy versus internal energy were also investigated in the current article. Based on the obtained result, the Epoxy material combined with UHPC material was proved to be a potential application in impact resistance design.

Predictive Modeling of Spring-Back Behavior in V-Bending of SS400 Steel Sheets under Elevated Temperatures Using Combined Hardening Laws

This research presents an innovative methodology for accurately predicting spring-back tendencies in V-bending of SS400 steel sheets under elevated temperatures. The study leverages extensive tensile test data to determine parameters for pure isotropic and kinematic hardening laws at varying temperatures, crucial inputs for Finite Element Method (FEM) simulations. While using pure isotropic or kinematic hardening laws alone has limitations, especially at elevated temperatures, a hybrid approach is recommended for robust predictive models in ABAQUS 6.13 software. To address this challenge, a novel method is introduced, utilizing flow stress curve ratios between elevated and room temperatures as a function of equivalent strain to derive combined hardening law parameters. Rigorous comparison of simulation and experimental results confirms the model’s effectiveness in predicting spring-back in the V-bending of SS400 steel sheets, particularly under elevated temperatures. This innovative approach enhances understanding of material behavior at high temperatures and improves predictive capabilities for designing and optimizing complex V-bending processes.

Investigating Ice Loads on Subsea Pipelines with Cohesive Zone Model in Abaqus

Subsea pipelines and cables placed in ice-prone regions may be at risk of iceberg damage. In particular, pipes that are not buried may come in direct contact with iceberg keels. Knowing the range of interaction forces helps to assess the types and magnitudes of potential damage. Experimental studies provide the most valuable data about the interaction forces, while numerical modeling may give insight into configurations that are difficult to study experimentally. This work applies the cohesive zone model to investigate the fracture behavior of ice samples. Simulations are performed in 2D with Abaqus explicit solver. Modeled interaction forces from multiple simulations are recorded and compared to understand how the geometry of the samples affects the fracture. Repeat interactions with different grain configurations are conducted to investigate associated variance in fracture patterns and loads. t-tests show that the force application angle and the indenter’s position significantly affect the fracture force.

Implementation of ABAQUS User Subroutines for Viscoplasticity of 316 Stainless Steel and Zircaloy-4

This paper describes the formulations for the viscoplasticity of metals based on the Chaboche and Delobelle model. The implementations of the viscoplastic models were detailed herein and then implemented via user subroutines for material models (UMAT) in ABAQUS. Two typical metals, i.e., 316 Stainless Steel and Zircaloy-4, were chosen as examples and their viscoplastic behaviors were captured. Numerical simulations are compared to reported experiments in order to validate the models and the UMAT codes. The typical viscoplastic behaviors of both metals, such as stress relaxation and creep, were captured well through the available experiments. We have publicized all the data and codes.

Fatigue strength assessment of riveted shear splices

AbstractOld‐steel riveted bridges are part of the heritage asset in many countries. Assessing the remaining life and fatigue strength of their structural riveted details is crucial in managing these structures. According to JRC‐ECCS document Assessment of Existing Steel Structures: Recommendations for Estimation of Remaining Fatigue Life, fatigue class 71 is recommended to estimate the fatigue strength of riveted details. However, the predicted fatigue behaviour can lead to excessively conservative estimates. Hence the research community is still focusing on the suitability of current recommendations. This work performs a numerical study to evaluate the fatigue strength of riveted double‐shear splices. Experimental fatigue test results are collected from the literature, and some are used to develop a finite element model in ABAQUS and Fe‐Safe. The adopted modelling fatigue approach is applied to investigate the fatigue behaviour of double‐shear riveted connections with different geometrical properties. The numerical results are compared with all collected data, showing the procedure's effectiveness in predicting the fatigue strength of double‐shear riveted splices. Finally, the numerical and experimental results are compared with the recommended S‐N curves.

Finite Element Analyses of Demountable Shear Connection in Cold‐Formed Steel‐Concrete Composite Beam Based on Experimental Data

AbstractThere is a surging demand for innovations that would increase the value of construction elements and materials in their life cycle. Therefore, the subject of this research is the shear connection in the floor composite system of cold‐formed steel and concrete slab. Composite systems can be further improved by a demountable type of shear connection, which shows good performance compared to traditional solutions but also allow for system demountability, fulfilling some sustainability policy aspects. Here, two configurations of CFS‐concrete composite systems with bolted shear connections were considered. The first configuration considers two directly connected back‐to‐back CFS profiles, while the second considers two back‐to‐back CFS profiles spaced apart simulating the presence of a corrugated web in between. Based on the experimental results of the second configuration, the numerical model in ABAQUS was developed and calibrated. A detailed comparison of the two configurations has been carried out. Additionally, the behaviour of considered configurations was also analysed regarding the number of bolts within the rib of the concrete slab. The obtained results show that close spacing of the shear connectors can prevent the development of their full bearing capacity.

Experimental and numerical study of a damage‐free self‐centring link for seismic resilient EBFs

AbstractSignificant progress has been made in recent years for the definition of seismic‐resilient structures, chasing the urgent need for structures able to return to undamaged, fully functional conditions in a short time after an extreme event. Seismic‐resilient steel structures have been widely investigated, mainly considering solutions based on moment‐resisting and concentrically braced frames. However, while the first category may be characterised by low stiffness, the second is often characterised by low ductility. Eccentrically Braced Frames (EBFs) allow overcoming these drawbacks and well‐balance stiffness, strength and ductility. This paper presents the numerical and experimental study of a damage‐free self‐centring link for EBFs. The proposed device uses post‐tensioned bars to control the self‐centring behaviour and friction devices to provide dissipation capacity. Experimental cyclic tests have been carried out to evaluate the response of the device. A 3D ABAQUS model has been developed to investigate the local response. Finally, a six‐storey EBF has been numerically investigated in OpenSees to evaluate the global response. Incremental Dynamic Analyses were performed demonstrating the increased seismic performance of the proposed solution.

Estimation of the displacement time history of high-rise building structures using limited measurement data and structural information

A method is proposed to estimate the seismic displacement time history of a high-rise building structure. The structure is simplified to a flexural-shear mass-spring model, and the optimal parameter values of the model are determined using particle swarm optimization. Limited measured acceleration and roof residual displacement data are used to calculate the model error in the optimization process. In this method, only the number of stories and the heights of each story are needed as known structural information. The displacement time history calculated for the optimal model is treated as the estimation of the actual response of the original structure. The responses of a 13-story reinforced-concrete frame-shear wall structure obtained from numerical simulation of the ABAQUS model are used to verify the performance of the method. The results show that the average estimation error of the maximum story displacement is 5.2% and that of the maximum inter-story drift ratio is 5.3%. Having the acceleration responses of 1/3–1/4 stories is sufficient to accurately estimate the story displacement and inter-story drift ratio if the root mean square noise-to-signal ratio of the acceleration is less than 30%. The shaking table test data of a 15-story reinforced-concrete shear structure are used to verify the method’s effectiveness; the average estimation error of the maximum story displacements of the 7th, 8th, and 15th stories is found to be 4.8%.