CAE Simulations Research Articles

Strength and fatigue behavior assessment of the SCALMALLOY® material to functionally adapt the performance of L-PBF components within CAE simulations

Strength and fatigue behavior assessment of the SCALMALLOY® material to functionally adapt the performance of L-PBF components within CAE simulations

A surrogate model based calibration method for structural adhesive joint progressive failure simulations

ABSTRACT An integrated adhesive material model calibration method is proposed for adhesively bonded joints’ deformation and progressive failure simulations under mixed loading modes. In this method, a surrogate model is trained to express the intrinsic numerical relationship between the key parameters (e.g., the yield normal stress and yield shear stress) and the simulated load-displacement curves of the bonded specimens. The parameter calibration process of the material model under multiple loading conditions is described as a multi-objective optimization problem. To minimize the load-displacement curve errors among the CAE simulation model and the experiment data, the model parameters are calibrated effectively based on the surrogate model using the genetic algorithm. The validity and efficiency of the proposed calibration method is verified by comparing the test data under various loading conditions. The better precision and efficiency indicates the potential of using this framework to effectively calibrate material properties without performing time-consuming CAE simulations.

Evaluate slip torque of an interference fit using preloaded, non-linear large strain simulation in MSC MARC

Automotive component assemblies have single or multiple non-linearities. These are either geometric, material or contact related non linearities. In the product assembly discussed in this paper, we came across preloaded, non-linear large strain i.e., to evaluate the slip torque of an interference fit. Generally, linear simulations are performed with all the three linear considerations, but in this problem statement there was compressive preload due to interference fit, which is carried further in the torque slip evaluation of the assembly. The material at the interference area is prone to fracture/crushing i.e., large strains, complete element destruction and new adaptive mesh formation therefore must be considered. So, to consider the Pre-Load as well as non-linear large strain conditions, CAE simulations were performed in MSC Marc Non-linear Solver. This paper would talk about in-depth results interpretation of Preloaded (Compression due to interference fit) and nonlinear large strain simulations to evaluate the rotational moment at which shaft begins to slip losing its interference fit. In Non-Linear simulation we were able to capture this dynamic interaction between the required portion of rotor and shaft and demonstrate the same with good accuracy.This activity of Pre-Loaded, Non-linear Large strain simulation helped us understand how mechanical system behavior is changing with respect to its mathematics or we can say accurate numerical interpretation.

Simulation Analysis of Graphene Addition on Polymeric Composite

Natural fibres in composite materials, such as kenaf fibres, are used to reinforce polypropylene (PP) due to their light weight and high mechanical performance required in various applications, such as automotive. Although natural fibres seem to be the most promising material, manufacturing parameters and material composition are crucial to determining balanced output performance. Therefore, this study provides essential knowledge on defining the parameters and the effect of addition of graphene content to kenaf fibres composites using computer simulation via Abaqus CAE software. Detailed analyses were compared with the experimental data of Young’s modulus and tensile strength. General static and dynamic explicit analyses were conducted using Abaqus CAE simulations, and set at 40 wt. % kenaf fibres, 0, 1, 3, and 5 wt. % graphene. Short kenaf fibres were utilised together with graphene nanoplatelets and prepared using a hot-pressing technique with the temperature set at 190 °C and pressure of 5 MPa for 5 min. The findings indicated that the simulation and experimental data from previous studies data congruent which is Young’s modulus and tensile strength increased with addition of graphene content. Thus, the simulated data could predict the experimental mechanical performance, in which 24 MPa of tensile strength was recorded for 3 wt. % of graphene additions.

High-Order Groove-Shape Curve Roll Design for Aluminum Alloy 7075 Wire Rolling

A Bézier curve groove-shape roll design method was proposed and compared to round-oval-round designs for the wire rolling process. CAE simulations were adopted to predict the rolling forces and torques required for the rolling process. The rolling torque required for the case of 28% vertical compression rate is 73% higher than the case of 12% compression rate. The curve fittings of the rolling torque and the compression force with respect to the compression rate were obtained with very high R-square values (0.99 and 0.98) in the first rolling pass. The rolling force required for the Bézier curve groove-shape design is no different compared to the oval design with the same compression rate, but the rolling torque requirement for the next rolling station is 6% less than the oval groove design. Furthermore, the equivalent strain distribution on the cross section of the product was uniform, and no fin flash defects occurred. The proposed Bézier curve groove-shape is a better design from the viewpoint of uniform product mechanical property requirement, and a larger compression rate per pass could be achieved.

Hood Flutter Under Transient Aerodynamic Loads

<div class="section abstract"><div class="htmlview paragraph">Automobile hood design is driven by many factors, such as strict government regulations, fuel economy, weight, manufacturability, aerodynamic performance, aesthetics, structural integrity, and pedestrian safety standards. The requirement of improved fuel economy and safety regulations like pedestrian protection drive designers to reduce the thickness of the hood parts and use lighter materials. This leads to significant reduction in the hood stiffness. The hood needs to withstand steady and unsteady aerodynamic loads and meet deflection and vibration targets. The susceptibility of the hood to adverse aero load response is increased as the stiffness of the hood is reduced.</div><div class="htmlview paragraph">The objective of this study is to develop a methodology to simulate hood behavior under transient aerodynamic loads in controlled environments. This study mainly focuses on developing fluid structure interaction methodology to simulate the behavior of the hood system under transient aerodynamic loads.</div><div class="htmlview paragraph">A flat plate approach was applied to create disturbance in wind flow to simulate a vehicle in front of the target vehicle in wind tunnel. This situation is simulated using computational fluid dynamics (CFD) software to generate transient aerodynamic loads.</div><div class="htmlview paragraph">The CAE simulations help to understand the hood behavior under transient aero load and mitigate the risk of excessive hood vibration in early development stages of the hood design.</div></div>

数値精度削減による高速有限要素解析

In most CAE simulations based on the finite element method, double-precision real numbers have been used. On the other hand, due to overwhelming demand for deep learning, low-precision arithmetic is now being introduced into general-purpose processors. By using low-precision real arithmetic for finite element analyses, we can effectively use the arithmetic unit originally equipped for deep learning and obtain advantages in terms of calculation speed. In this study, we propose a fast finite element analysis assisted by deep learning, where low-precision arithmetic is aggressively used to accelerate calculation speed. In the proposed method, deep learning indicates where to use lower precision computation for calculation speed. Here, for the first try, the effect of low precision numbers on numerical quadrature of finite elements is quantitatively investigated through sample analyses.

Interactive Visual Analysis Engine for High-Performance CAE Simulations

<p indent="0mm">Large-scale simulation data poses new challenges to CAE design and analysis. The coherent interaction between pre-processing and post-processing is weak, and the visual interaction of large-scale data is low. Therefore, an interactive visual analysis engine for high-performance CAE simulations is proposed. Firstly, a hybrid data model that efficiently couples geometric models and computational meshes is constructed. Secondly, a parallel visualization pipeline is developed for the coherent interaction of pre-processing and post-processing. Finally, a GPU photorealistic rendering based on lightweight primitives extracted from the external surface of volume meshes is implemented to support real-time high quality CAE design and analysis. The engine has been integrated into aeroengine CAE simulation Apps of China. The results show that it can smoothly support the interactive design and analysis of large-scale simulation applications. Based on this engine, the interactive performance of one-click import and rendering of the Trent-1000 engine model, including tens of millions of unstructured grids, is more than 8 times higher than that of ANSYS software.

Analysis of Fuselage Using Static and Thermal Interface for Different Joints

Fuselage forms the main structure of the aircraft that accommodates the passenger and cargo. The fuselage is continuously subjected to various loads during flight as well as after landing. The integrity of the fuselage-structure is very important for the safety of the aircraft. This project describes a conceptual design of fuselage structure by using CAD software. This project aims to design and analysis of fuselage using static and thermal interface for different joints (riveted, bonded, hybrid) loads for static and thermal stiffness. For this purpose, CAE simulations will be performed on a fuselage model using static and thermal conditions.

The effect of graphene addition on the Young’s modulus and tensile strength of kenaf fibre composites

Natural fibres such as kenaf fibres may be used to reinforce polymer matrices such as polypropylene (PP). Such composite materials are in demand for the production of interior components for automotive vehicles due to their low density (1.2 g/cm³) and good mechanical properties (Young’s modulus of 11 GPa and tensile strength of 780 MPa). The main objective of this study is to determine the effect of the addition of graphene fillers to the tensile strength and Young’s modulus of kenaf fibre composites. For this kenaf/graphene/polypropylene (PP) composites are to be studied via computer simulations using Abaqus CAE software and to compare the experimental data of Young’s modulus and tensile strength of the composite from previous researchers with the results of the simulations. For the Abaqus CAE simulations, general static and dynamic explicit analyses were conducted and set at 20 wt. % kenaf fibres, 0, 1, 3, to 5 wt. % graphene. The highest value of Young’s modulus was 1 600 MPa achieved with the material with composition of PP/kenaf/graphene 5 wt. % while the highest value of tensile strength was achieved by the composition of PP/kenaf/graphene 1 wt. % at 23.07 MPa. On the other hand, the values of tensile strength increase with the addition of graphene (1 wt. %) at first due to the improvement of interface adhesion between the polymer matrix and non-organic particles. Further addition of graphene content (3 – 5 wt. %) results in a decrease of tensile strength due to the presence of agglomeration and defects such as voids and fibre pull-outs which weakens the adhesion between the fibres and matrix. The addition of graphene to PP/kenaf composites was proved to improve the Young’s modulus and tensile strength of the materials. This improves the suitability of the materials in the production of interior components for automotive vehicles.

A review on biomechanics of the hallux valgus pathology and its surgical treatments

The present paper aims at an interdisciplinary field, regarding biomechanics aspects of the Hallux Valgus, which is a frequent deformity in our days. Owing to the importance of the study theme and the social impact, we consider it very important that the state of the art should be as detailed as possible, due to this condition being frequent in women and older people. The review will target recent research of the biomechanics of the foot, the test subjects being in normal conditions and also patients affected by Hallux valgus deformities; likewise, it will define important geometrical elements, which are required for the engineering approach of the issue. As well, the 3D modelling of the condition will be taken into consideration, beside with the surgical procedures and conservative treatments. Another important aspect covered in the paper is regarding the research and CAE simulations using the FEM, alongside with the work stands developed in this area. The bibliographic research found on the most important journals and databases shall be synthesized and structured in order to highlight the big picture of a specific research regarding a future PhD thesis.

CAE analysis and simulations of technological processes of selected high strength steels

The article of authors deals with the design of the structural part of the bodywork in the CAE system CATIA using the CAE software solutions of the Autoform system, which are based on the finite element method. This design was subsequently implemented into the design of dies in order to achieve the most efficient and high-quality dies, which are increasingly required in industrial practice for lifetime and functionality. Three types of high-strength steels TRIP HCT780T, DP-HCT780X and CP-HCT780C with approximately the same tensile strength were selected for the experiments. Based on the input parameters, simulations were implemented and the results obtained from the simulations will be the basis for selecting the most optimal variant. The main measurable and evaluative factor was the outputs obtained from the FLD diagrams.

Deep learning enhanced digital twin for Closed-Loop In-Process quality improvement

A digital twin framework is presented for assembly systems with compliant parts fusing sensors with deep learning and CAE simulations. Its underlying concept, ‘process capability space,’ updates iteratively during evolving tasks of new product introduction with resulting model fidelity able to simulate dimensional, geometric and weld quality of parts and assemblies; isolate root causes of quality defects; and, suggest corrective actions for automatic defects mitigation; thereby, enabling ‘Closed-Loop In-Process (CLIP) quality improvement’ during assembly system development. Results, using the first fully digitally developed remote laser welding process for aluminium doors, yielded a right-first-time rate of >96% for door assembly cell development.

The Optimization Wire Drawing Die Design for Aluminum A1050 and A1070

Wire drawing is a common used process to reduce the diameter of a small rod or a wire. The parameters of drawing die design such as die angle, bearing length, entrance fillet, and the drawing ratio of each pass are crucial to control the quality of a drawn wire. Taguchi method was adopted to optimize the drawing die geometry design. The lubrication conditions were taken into consideration to observe the effect of friction on the dimension accuracy of the drawn wires. The optimum combination of the drawing die design using 20% of reduction ratio is semi die angle 9 degrees, bearing length 1.2mm and entrance fillet 0.4mm. Two types of aluminum alloy 1070 and 1050 were tested using lubricants sodium sulfide (Na2S), graphite, and drawing oil, respectively. The lubrication effect of sodium sulfide is the best to achieve the lowest drawing load. The lubricant Na2S had the best performance in terms of lowest maximum drawing force for both of A1050 and A1070. The final diameters of the drawn wires were very close to the specification 4.0 mm. The CAE simulations were able to find the optimum design of die. The designed drawing machine was capable of carrying out the experiments and obtains consistent results.

Optimization of Passenger Car Door Impact Beam using Quasi Static CAE Analysis

Automotive side impacts are particularly dangerous as location of impact is very close to the passenger, who can be immediately reached by the impacting vehicle. FMVSS 214 static is a US safety regulation for occupant safety during side impacts, in which the vehicle is tested at static loading conditions to measure its load baring capacity and integrity of side closures. The CAE load case, virtually simulating the test, was handled as a quasi-static problem in this study. Impact beam is a component that helps in improving vehicle passive safety performance during side impacts by minimizing door intrusion to the occupant cabin. It plays an important role in achieving side impact regulatory norms. Through this study, a mass optimized front door impact beam design was developed for a passenger car with the help of CAE simulations; FMVSS 214S regulation norms are met. Component thickness, material and cross section shape were the design variables considered for the study. A methodology to perform the component level simulation of the impact beam loading such that it replicates component behaviour during full vehicle simulation was developed. This has helped in reducing the total problem calculation time in solver. This also has minimized the computational cost for the project. CAE simulations required for the study were done using LS-DYNA. ANSA and PRIMER were used as pre-processors and hyper-graph and meta-post were used for post processing.

Fastener products lightweight design and forming process simulation

In this research, an integrated design system was established to design the product of nuts with flange and generate the lightweight geometry of product. The multi-stage forming process was evaluated using the CAE simulations. The topology optimization method was used to achieve the lightweight design, that included keeping necessary geometrical features and remove the excess volumes. The topological discrete model had been remodelled into a meaningful geometry which is able to satisfy the requirement of proof load of fastener specification. The final design of the lightweight geometry was adopted to test the capability of carrying proof load required using CAE simulations with the boundary conditions of the related ASTM standard. In the evaluation stage, the finite element method was used to do the topology optimization, the proof load evaluation, the forging process and the die stress analysis. The simulation results showed the lightweight design was able to reduce the weight of product and maintain enough mechanical strength. The proposed process and die designs were able to obtain the lightweight product without defects.

Flexible roll forming of U-section product with curved bending profile using advanced high strength steel

A flexible roll forming machine was designed and made using CAD/CAE technologies. The Ethernet control system was adopted to control the motions of forming rolls and stands simultaneously. The forming path was generated in according to the longitudinal roll forming profile of the product geometry. The blank position was monitored using measuring wheel encoders to compensate the blank shifting error. The CAE simulations were carried out to evaluate the feasibility of the process and die designs. The roll-formed part was measured by the experiment tests. The experimental results had shown the error compensation proposed was able to reduce shifting error from 4 mm to 0.5 mm.

Analytical modelling of twist beam axles

This paper presents an efficient method for concept design of twist beam axles and other similar mechanical systems by using analytical models. A concept of twist beam axles has been idealised as a beam model with extensive parametric variables. With this model many stiffness and kinematic characteristics which are typically required for twist beam axles can be determined analytically and accurately within a few seconds. Compared to the conventional method with numerous CAD and CAE iterations this new method can substantially reduce the development time, including human resources and computation time. Several axles have been evaluated and verified. The results are well comparable with those of CAE simulations. This very fast and efficient concept development can be coupled with mathematical optimisation algorithms in order to obtain an ideal starting position for further CAD/CAE-based product development in detail.

Analytical modelling of twist beam axles

This paper presents an efficient method for concept design of twist beam axles and other similar mechanical systems by using analytical models. A concept of twist beam axles has been idealised as a beam model with extensive parametric variables. With this model many stiffness and kinematic characteristics which are typically required for twist beam axles can be determined analytically and accurately within a few seconds. Compared to the conventional method with numerous CAD and CAE iterations this new method can substantially reduce the development time, including human resources and computation time. Several axles have been evaluated and verified. The results are well comparable with those of CAE simulations. This very fast and efficient concept development can be coupled with mathematical optimisation algorithms in order to obtain an ideal starting position for further CAD/CAE-based product development in detail.

Fracture behavior of Inconel 718 sheet in thermal-aided deformation considering grain size effect and strain rate influence

In this paper, the fracture behavior of Inconel 718 sheets in thermal-aided deformation processes is elucidated, accompanied by high-temperature fracture photography analysis, considering the effect of grain size and strain rate. Uniaxial tests were conducted under varied test conditions. A segmentation phenomenon was observed in the Hall-Petch curves for the fracture stress at lower strain rates, which disappeared at higher strain rates. Moreover, the fracture strain is predicted by the Cockcroft & Latham criterion with a modified Voce constitutive model. Based on the fracture photographs acquired by scanning electron microscopy (SEM), a two-step fracture mechanism was proposed and shown for Inconel 718 thin sheets. Furthermore, thin sheet fracture was found to be influenced by inclusions, which was verified by CAE simulations. This article thus provides an in-depth discussion of fracture behavior of Inconel 718 thin sheets, which was influenced by the comprehensive effects of the grain size distribution, strain rate influence, local element composition, and the second-phase particles or inclusions.