A Deconvolution Scheme for Determination of Seismic Loads in Finite‐Element Analyses

2013 ◽  
Vol 103 (1) ◽  
pp. 258-267 ◽  
Author(s):  
S. H. Ju
Keyword(s):  
Finite Element ◽  
Seismic Loads ◽  
Finite Element Analyses

Constraint Solutions for Cracked Plates and Cylinders

2016 ◽  
Author(s):  
Caroline Meek ◽  
Marius Gintalas ◽  
Andrew H. Sherry ◽  
Robert A. Ainsworth
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Biaxial Loading ◽  
Analytical Determination ◽  
Plastic Collapse ◽  
Finite Element Analyses ◽  
Elastic Plastic ◽  
Cracked Plates ◽  
Computing Effort

There is little advice in fitness for service procedures for assessing constraint parameters T (elastic) and Q (elastic plastic) for biaxially loaded plates and cylinders. This paper presents the analytical determination of T stresses for biaxially loaded plates and the determination of Q for plates and cylinders using finite element analyses. It demonstrates the extent to which T can be used to conservatively predict Q and how, near collapse, Q can be estimated from the stress field corresponding to plastic collapse, enabling a significant reduction in computing effort. The effect of biaxial loading of plates and cylinders on these parameters is discussed as well as the differences found when comparing the values for plates and cylinders.

Industrial Application of the Method “Early Determination of Product Properties”

1998 ◽  
Author(s):  
Udo Lindemann ◽  
Ralf Stetter
Keyword(s):  
Finite Element ◽  
Product Development ◽  
Development Process ◽  
Product Development Process ◽  
Complex Method ◽  
Finite Element Analyses ◽  
Negative Effects ◽  
Influencing Parameters ◽  
Industrial Company

Abstract Nothing is more critical for the success of a project than a design flaw that remains undetected until the product is in production or even handed over to the customer. In order to prevent the negative effects of undetected flaws, the method “early determination of product properties” has been developed at the Chair of Design at the Technische Universität München. In this paper the introduction of the method in a mid-size industrial company and the first resulting tool, the Parameter Checklist, are described. The presented research started with a detailed analysis of the product development process in the industrial company. In order to introduce a complex method in an industrial company, many aspects of the situation of the designers, from existing tools and procedures to the designers’ capabilities have to be considered. Because of this, the method was divided into distinct ideas, stages and tools, and compared individually to the situation given. On this basis a first methodical tool was developed, intended to support designers while using the method. The tool called Parameter Checklist supports designers in planning analyses (e.g. tests with physical prototypes, finite element analyses) and in interpreting the results of these analyses. Furthermore, by using the tool, a database is filled that provides enough information to reconstruct the described analyses. In contrast with conventional testing instructions, the Parameter Checklist contains an explicit description of the model, in some respects found to be important, and a list of the influencing parameters. This is the basis for both a simple but conscious form of analysis planning and a more thorough interpretation of the analysis results.

Decomposition-Based Assembly Synthesis of Space Frame Structures Using Joint Library

2004 ◽  
Author(s):  
Naesung Lyu ◽  
Kazuhiro Saitou
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Structural Characteristics ◽  
Finite Element Analyses ◽  
Space Frame ◽  
Multi Objective Genetic Algorithm ◽  
Joint Location ◽  
The Cross

This paper presents a method for identifying the optimal designs of components and joints in the space frame body structures of passenger vehicles considering structural characteristics, manufacturability and assembleability. Dissimilar to our previous work based on graph decomposition, the problem is posed as a simultaneous determination of the locations and types of joints in a structure and the cross sections of the joined structural frames, selected from a predefined joint library. The joint library is a set of joint designs containing the geometry of the feasible joints at each potential joint location and the cross sections of the joined frames, associated with their structural characteristics as equivalent torsional springs obtained from the finite element analyses of the detailed joint geometry. Structural characteristics of the entire structure are evaluated by finite element analyses of a beam-spring model constructed from the selected joints and joined frames. Manufacturability and assembleability are evaluated as the manufacturing and assembly costs estimated from the geometry of the components and joints, respectively. The optimization problem is solved by a multi-objective genetic algorithm using a direct crossover. A case study on an aluminum space frame (ASF) of a middle size passenger vehicle is discussed.

Decomposition-Based Assembly Synthesis of Space Frame Structures Using Joint Library

2004 ◽  
Vol 128 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Naesung Lyu ◽  
Kazuhiro Saitou
Keyword(s):  
Finite Element ◽  
Cross Sections ◽  
Structural Characteristics ◽  
Finite Element Analyses ◽  
Space Frame ◽  
Passenger Vehicles ◽  
Joint Location ◽  
The Cross

This paper presents a method for identifying the optimal designs of components and joints in the space frame body structures of passenger vehicles considering structural characteristics, manufacturability, and assembleability. Dissimilar to our previous work based on graph decomposition, the problem is posed as a simultaneous determination of the locations and types of joints in a structure and the cross sections of the joined structural frames, selected from a predefined joint library. The joint library is a set of joint designs containing the geometry of the feasible joints at each potential joint location and the cross sections of the joined frames, associated with their structural characteristics as equivalent torsional springs obtained from the finite element analyses of the detailed joint geometry. Structural characteristics of the entire structure are evaluated by finite element analyses of a beam-spring model constructed from the selected joints and joined frames. Manufacturability and assembleability are evaluated as the manufacturing and assembly costs estimated from the geometry of the components and joints, respectively. The optimization problem is solved by a multiobjective genetic algorithm using a direct crossover. A case study on an aluminum space frame of a midsize passenger vehicle is discussed.

scholarly journals Determination of the Crack Resistance Parameters at Equipment Nozzle Zones Under the Seismic Loads Via Finite Element Method

2018 ◽  
Vol 48 (1) ◽  
pp. 69-75
Author(s):  
Vladyslav Kyrychok ◽  
Vasyl Torop
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Pressure Vessel ◽  
Residual Life ◽  
Pressure Vessels ◽  
Accurate Estimation ◽  
Seismic Loads ◽  
Finite Element Program ◽  
Element Program

Abstract The present paper is devoted to the problem of the assessment of probable crack growth at pressure vessel nozzles zone under the cyclic seismic loads. The approaches to creating distributed pipeline systems, connected to equipment are being proposed. The possibility of using in common different finite element program packages for accurate estimation of the strength of bonded pipelines and pressure vessels systems is shown and justified. The authors propose checking the danger of defects in nozzle domain, evaluate the residual life of the system, basing on the developed approach.

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