Modeling of CPACS-based fuselage structures using Python

2017 ◽  
Vol 89 (5) ◽  
pp. 644-653
Author(s):  
Jan-Niclas Walther ◽  
Michael Petsch ◽  
Dieter Kohlgrüber
Keyword(s):  
Finite Element ◽  
Aircraft Design ◽  
Structural Data ◽  
Automatic Generation ◽  
Model Generation ◽  
Finite Element Models ◽  
Data Format ◽  
Content Type ◽  
Aircraft Fuselage ◽  
Tool Performance

Purpose The purpose of this paper is to present some of the key achievements. At DLR, a sophisticated interdisciplinary aircraft design process is being developed, using the CPACS data format (Nagel et al., 2012; Scherer and Kohlgrüber, 2016) as a means of exchanging results. Within this process, TRAFUMO (Scherer et al., 2013) (transport aircraft fuselage model), built on ANSYS and the Python programming language, is the current tool for automatic generation and subsequent sizing of global finite element fuselage models. Recently, much effort has gone into improving the tool performance and opening up the modeling chain to further finite element solvers. Design/methodology/approach Much functionality has been shifted from specific routines in ANSYS to Python, including the automatic creation of global finite element models based on geometric and structural data from CPACS and the conversion of models between different finite element codes. Furthermore, a new method for modeling and interrogating geometries from CPACS using B-spline surfaces has been introduced. Findings Several new modules have been implemented independently with a well-defined central data format in place for storing and exchanging information, resulting in a highly extensible framework for working with finite element data. The new geometry description proves to be highly efficient while also improving the geometric accuracy. Practical implications The newly implemented modules provide the groundwork for a new all-Python model generation chain, which is more flexible at significantly improved runtimes. With the analysis being part of a larger multidisciplinary design optimization process, this enables exploration of much larger design spaces within a given timeframe. Originality/value In the presented paper, key features of the newly developed model generation chain are introduced. They enable the quick generation of global finite element models from CPACS for arbitrary solvers for the first time.

Flexural bearing capacity of RC hollow slab beam strengthened by steel plates of different thicknesses

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Long Liu ◽  
Lifeng Wang ◽  
Ziwang Xiao
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Steel Plate ◽  
Plate Thickness ◽  
Research Field ◽  
Steel Plates ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Content Type ◽  
Flexural Bearing Capacity

PurposeThe flexural reinforcement of bridges in-service has been an important research field for a long time. Anchoring steel plate at the bottom of beam is a simple and effective method to improve its bearing capacity. The purpose of this paper is to explore the influence of anchoring steel plates of different thicknesses on the bearing capacity of hollow slab beam and to judge its working status.Design/methodology/approachFirst, static load experiments are carried out on two in-service RC hollow slab beams; meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Finally, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsWhen steel plates of different thicknesses are adopted to reinforce RC hollow slab beams, the bearing capacity increases with the increase of the steel plate thickness in a certain range. But when the steel plate thickness reaches a certain level, bearing capacity is no longer influenced. The displacement ductility coefficient decreases with the increase of steel plate thickness.Originality/valueBased on experimental study, this paper makes an extrapolation analysis of the bearing capacity of hollow slab beams reinforced with steel plates of different thicknesses through finite element simulation and discusses the influence on ductility. This method not only ensures the accuracy of bearing capacity evaluation but also does not need many samples, which is economical to a certain extent. The research results provide a basis for the reinforcement design of similar bridges.

Comparison of flexural capacity of different hollow slab beams with/without pavement layer reinforced by steel plates

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Long Liu ◽  
Lifeng Wang ◽  
Ziwang Xiao
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Steel Plate ◽  
Plate Thickness ◽  
Experimental Results ◽  
Nonlinear Material ◽  
Finite Element Models ◽  
Rc Beams ◽  
Flexural Capacity ◽  
Content Type

PurposeReinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.Design/methodology/approachFirst, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsThe experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.Originality/valueIn this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.

scholarly journals The Automatic Generation of Finite Element Models for Different Analysis Levels

1994 ◽  
Vol 1994 (176) ◽  
pp. 359-365 ◽  
Author(s):  
Hideomi Ohtsubo ◽  
Katsuyuki Suzuki ◽  
Tokimasa Hiraki ◽  
Yasumi Kawamura
Keyword(s):  
Finite Element ◽  
Automatic Generation ◽  
Finite Element Models

Investigating the fire performance of LSF wall systems using finite element analyses

2017 ◽  
Vol 8 (4) ◽  
pp. 354-376 ◽  
Author(s):  
Mohamed Rusthi ◽  
Poologanathan Keerthan ◽  
Mahen Mahendran ◽  
Anthony Ariyanayagam
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Full Scale ◽  
Finite Element Models ◽  
Fire Tests ◽  
Fire Performance ◽  
Load Bearing ◽  
Content Type ◽  
System Configurations ◽  
Wall System

Purpose This research was aimed at investigating the fire performance of LSF wall systems by using 3-D heat transfer FE models of existing LSF wall system configurations. Design/methodology/approach This research was focused on investigating the fire performance of LSF wall systems by using 3-D heat transfer finite element models of existing LSF wall system configurations. The analysis results were validated by using the available fire test results of five different LSF wall configurations. Findings The validated finite element models were used to conduct a parametric study on a range of non-load bearing and load bearing LSF wall configurations to predict their fire resistance levels (FRLs) for varying load ratios. Originality/value Fire performance of LSF wall systems with different configurations can be understood by performing full-scale fire tests. However, these full-scale fire tests are time consuming, labour intensive and expensive. On the other hand, finite element analysis (FEA) provides a simple method of investigating the fire performance of LSF wall systems to understand their thermal-mechanical behaviour. Recent numerical research studies have focused on investigating the fire performances of LSF wall systems by using finite element (FE) models. Most of these FE models were developed based on 2-D FE platform capable of performing either heat transfer or structural analysis separately. Therefore, this paper presents the details of a 3-D FEA methodology to develop the capabilities to perform fully-coupled thermal-mechanical analyses of LSF walls exposed to fire in future.

Fuselage Structural-Acoustic Modeling for Structure-Borne Interior Noise Transmission

1988 ◽  
Vol 110 (2) ◽  
pp. 226-233 ◽  
Author(s):  
J. F. Unruh ◽  
S. A. Dobosz
Keyword(s):  
Finite Element ◽  
Structural Models ◽  
Local Area ◽  
Interior Noise ◽  
Acoustic Modeling ◽  
Finite Element Models ◽  
Aircraft Fuselage ◽  
Structural Details ◽  
Noise Transmission ◽  
Structural Definition

Detailed finite element models of a fuselage structure and acoustic cabin volume of a laboratory based prototypical aircraft fuselage were generated for the purpose of studying the predictive capabilities of deterministic modeling procedures for structure-borne noise transmission. Comparative predictions are made to measured wing-to-fuselage attach point inertances and interior noise to force responses. Several structural models with increased structural definition were evaluated. It was found that to accurately predict wing-to-fuselage attach point inertances required increased local area structural definition, while interior noise can be reasonably well predicted without paying additional attention to local area structural details.

Automatic generation of accurate subject-specific bone finite element models to be used in clinical studies

2004 ◽  
Vol 37 (10) ◽  
pp. 1597-1605 ◽  
Author(s):  
Marco Viceconti ◽  
Mario Davinelli ◽  
Fulvia Taddei ◽  
Angelo Cappello
Keyword(s):  
Finite Element ◽  
Clinical Studies ◽  
Automatic Generation ◽  
Finite Element Models ◽  
Subject Specific

scholarly journals The method of synthesis of finite-element model of strengthened fuselage frames

2013 ◽  
pp. 80-90
Author(s):  
В. В. Борисов ◽  
В. В. Сухов
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Finite Element Model ◽  
User Interfaces ◽  
Element Model ◽  
Finite Element Models ◽  
Synthesis Algorithm ◽  
Model Synthesis ◽  
Aircraft Fuselage ◽  
The Finite Element Model

One of the main problems, which solved during the design of transport category aircraft, is problem of analysis of the stress distribution in the strengthened fuselage frames structure. Existing integral methods of stress analysis does not allow for the mutual influence of the deformation of a large number of elements. The most effective method of solving the problem of analysis of deformations influence on the stress distribution of structure is finite element method, which is a universal method for analyzing stress distribution arbitrary constructions.This article describes the features of the finite element model synthesis of the strengthened fuselage frames structure of the aircraft fuselage transport category. It is shown that the finite element model of strengthened frames can be synthesized by attaching additional finite element models of the reinforcing elements to the base finite element model which is built by algorithm which is developed for normal frame. For each reinforcing element developed a separate class of finite element model synthesis algorithm. The method of synthesis of finite element model of strengthened frame, which are described in this article, developed for object-oriented information technology implemented in an object-oriented data management system "SPACE".Finite-element models of the reinforcing elements are included in the finite element model of the fuselage box after the formation of a regular finite element model of the fuselage box. As the source data for the synthesis of finite element models of the reinforcing elements used the coordinates of the boundary sections nodes of existing finite element models of conventional frames.Reinforcing elements belong to the group of irregular structural elements that connect regular elements of the cross set with different elements that are not intended for the perception and transmission of loads. The only exceptions are the vertical amplification increasing the stiffness of  frames in a direction parallel to the axis OY.Source data input for the synthesis of finite element models of the reinforcing elements can occur only through the individual user interfaces that supported by objects of the corresponding classes. Structure of user interfaces depends on the number and type of additional data that required for the synthesis of finite element models of the reinforcing elements. For example, for the synthesis of structures of finite element models of horizontal beams that support the floor of cargo cabin, you must specify the distance between the upper surface of the beam and the horizontal axis of the fuselage, as well as the height of the beam section. For the synthesis of the structure of the finite element model of vertical reinforcing element is enough to specify the distance between the its inner belt and the a vertical axis of symmetry of the fuselage.And in both cases you must to specify a reference to the basic finite element model, by selecting from a list of frame designations. List of frames, as well as links to objects containing the appropriate finite-element models, must be transmitted from an object which references to the level of decomposition, in which the general model of the fuselage box is created.Finite-element models of the reinforcing elements include two groups of nodes. The first group is taken from an array of nodes, which is transmitted from the base finite element model. The second group is formed by the synthesis algorithm of finite element model of the selected class reinforcing element. Therefore, the synthesis of finite element models of the reinforcing elements starts with the formation of their local model versions. On the basis of these models are formed temporary copies, which are transmitted to the general finite element model of the box. This should be considered when developing of data conversion algorithm of data copying from a local finite element model to the temporary copy.Based on this analysis, we can conclude that this method improves the quality of the design of the aircraft fuselage, increasing the amount of structure variant number and reduce the likelihood of errors.

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