Computational analysis of thermal and structural failure criteria of a multi-storey steel frame exposed to fire

Analisis Numerik Part Bulkhead Pada Sub System Wing To Fuselage Joinner Assembly Pesawat Aerobatik Menggunakan Metode Elemen Hingga

Jurnal Teknologi Kedirgantaraan ◽

10.35894/jtk.v6i1.34 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Enggar Kristian ◽

Agus Suprianto ◽

Nurhadi Pramana ◽

Sahril Afandi ◽

Endah Yuniarti

Keyword(s):

Incidence Angle ◽

Failure Criteria ◽

Topological Optimization ◽

Structural Failure ◽

Topological Approach ◽

Approach Method ◽

Margin Of Safety ◽

Problem Solving Process ◽

Aluminum Alloy 7075 ◽

Geometric Variation

Analisis rancangan bulkhead dilakukan untuk memperoleh geometri terbaik untuk mencari berat yang efisien dengan mengubah geometri bentuk pada bulkhead yang merupakan sub system wing to fuselage untuk pesawat berkategori aerobatik dan berat yang optimal yang memenuhi persyaratan regulasi FAR 23 dan mengetahui respon distribusi tegangan, bending yang dihasilkan dan kriteria kegagalan struktur berdasarkan variasi geometri bentuk bulkhead. Pada penelitian ini untuk analisis statik bulkhead untuk pesawat berkategori aerobatik menggunakan material Aluminium Alloy 7075-T6 dan menggunakan metode pendekatan Schrenk untuk menghitung beban eksternal distrbusi gaya angkat pada sayap. Selain itu dilakukan proses optimisasi berat bulkhead berdasarkan metode pendekatan topologi yaitu perubahan geometri bentuk pada bulkhead untuk mereduksi berat, sudut insiden spar yang berbeda dan menghitung magin of safety. Proses penyelesaian masalah menggunakan perangkat lunak metode elemen hingga (Abaqus CAE). Optimisasi topologi pada part bulkhead sudut insidet 0° dan 4° menghasilkan volume yang berkurang pada benda sehingga mereduksi berat, tetapi nilai dari margin of safety MS = 0. The bulkhead design analysis was carried out to obtain the best geometry to find an efficient weight by changing the shape geometry of the bulkhead which is a sub-system of the wing to the fuselage for an aircraft categorized as aerobatics and an optimal weight that meets the requirements of FAR 23 regulations and sees the stress distribution response, the resulting bending and structural failure criteria based on the geometric variation of bulkhead shapes. In this study, to analyze the bulkhead static for an aerobatic category aircraft using Aluminum Alloy 7075-T6 material and using the Schrenk Approximation method to calculate the external distribution load of lift force on the wing. In addition, the optimization of bulkhead weight based on the topological approach method is to change the shape geometry of the bulkhead to reduce weight, in different spar incidents and calculate margin of safety. The problem solving process uses finite element method software (Abaqus CAE). Topological optimization of the bulkhead part with an incidence angle of 0 ° and 4 ° results in a reduced volume of the object so that it reduces weight, but the value of the margin of safety MS = 0.

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Symbolic Algebra and Theorem Proving for Failure Criteria Reduction

Volume 2: 31st Computers and Information in Engineering Conference, Parts A and B ◽

10.1115/detc2011-47737 ◽

2011 ◽

Author(s):

John G. Michopoulos ◽

Athanasios Iliopoulos

Keyword(s):

Theorem Proving ◽

Strain Energy ◽

Failure Criteria ◽

Orthotropic Materials ◽

Structural Failure ◽

Symbolic Algebra ◽

Symbolic Computing ◽

Strain Energy Density Function ◽

Bner Basis ◽

Strain Space

The present paper reports on recent efforts of utilizing symbolic computing for identifying failure criteria cross reducibility from the perspective of theorem proving. Utilizing equational theorem proving algorithms and Gro¨bner Basis polynomial theorem provers implemented in Mathematica we have proven a number of interesting theorems related to the area of structural failure criteria for anisotropic and particularly orthotropic materials. The main contribution of this work is the demonstration of the tremendous utility of symbolic algebra for engineering applications as well as the demonstration of the idea that all failure criteria presented in the literature up to know can be proven under certain conditions to be special forms of general criteria relating to the strain energy density function associated with material continua. Two specific examples are presented and discussed along with a theorem proving the existence of a dual form of all stress space based criteria to equivalent one expressed in strain space.

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Assessment of Current High-Temperature Design Methodology Based on Structural Failure Tests

Journal of Pressure Vessel Technology ◽

10.1115/1.3264890 ◽

1987 ◽

Vol 109 (2) ◽

pp. 160-168 ◽

Cited By ~ 3

Author(s):

J. M. Corum ◽

W. K. Sartory

Keyword(s):

High Temperature ◽

Design Methodology ◽

Service Failure ◽

Failure Criteria ◽

The United States ◽

Department Of Energy ◽

Structural Failure ◽

Inelastic Analysis ◽

Inelastic Responses ◽

Asme Code

A mature design methodology, consisting of inelastic analysis methods provided in U.S. Department of Energy guidelines and failure criteria contained in ASME Code Case N-47, exists in the United States for high-temperature reactor components. The objective of this paper is to assess the adequacy of that overall methodology by comparing predicted inelastic deformations and lifetimes with observed results from structural failure tests and from an actual service failure. Comparisons are presented for three structural cases: 1) nozzle-to-spherical shell specimens, emphasizing stresses at structural discontinuities; 2) welded structures, emphasizing metallurgical discontinuities; and 3) thermally loaded cylinders and pipes, emphasizing thermal discontinuities. The comparisons between predicted and measured inelastic responses are generally reasonable; quantities are sometimes overpredicted somewhat and sometimes underpredicted. However, even seemingly small discrepancies in predicted stresses and strains can have a significant effect on life, which is thus not always as closely predicted. For a few cases, the lifetimes are substantially overpredicted, which raises questions regarding the methodology and/or the adequacy of the current design margins.

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Computational Analysis of Structural Defects in Silica Aerogels

MRS Advances ◽

10.1557/adv.2019.362 ◽

2019 ◽

Vol 4 (46-47) ◽

pp. 2479-2488

Author(s):

Hunter Gore ◽

Luis Caldera ◽

Xiao Shen ◽

Firouzeh Sabri

Keyword(s):

Computational Analysis ◽

Silica Aerogels ◽

Structural Defects ◽

Experimental Setup ◽

Proof Of Concept ◽

Structural Failure ◽

Insulating Materials ◽

Technological Advances ◽

Defective Region ◽

Formation Of Cracks

AbstractTechnological advances in synthesis and preparation of aerogels have resulted in formulations that have the mechanical integrity (while retaining flexibility) to be utilized in a broad range of applications and have overcome the initial brittleness that this class of materials was once known for. Both structural and functional aerogels show a drop in performance when subjected to certain cyclic thermal or impact loading due to the wear and formation of cracks, which reduces their lifespan. Here we present the proof-of-concept of a computational toolset that connects the change in thermal profile to structural failure and degradation. In combination with an appropriate finite element (FEM) solver, we have developed a genetic algorithm that can reconstruct the size and shape of the defective region in silica aerogels given the temperatures from a sensor grid. Results show that a heatmap can be used as the foundation for reconstructing faults and defects in thermally insulating materials. Furthermore, the model developed in this study can be expanded to accommodate other material types. Experimental setup can used to benchmark and refine the computational toolset.

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