scholarly journals The effect of fillet radius and length of the thick-walled cylinder on Von Mises stress and safety factor for rocket motor case

2020 ◽  
Author(s):  
Lasinta Ari Nendra Wibawa ◽  
Kuncoro Diharjo ◽  
Wijang Wisnu Raharjo ◽  
Bagus Hayatul Jihad
Author(s):  
Cho-Pei Jiang ◽  
Ching-Wei Wu ◽  
Yung-Chang Cheng

An integrating optimization procedure is presented to improve the von Mises stress and fatigue safety factor for a handlebar stem system in a bicycle system. The optimization procedure involves uniform design of experiment, Kriging interpolation, genetic algorithm, and nonlinear programming method. Using ANSYS/Workbench software and the ISO 4210 bicycle handlebar stem testing standard, the von Mises stress for the lateral bending test simulation and the fatigue safety factor for the fatigue test simulation is calculated. The von Mises stress and fatigue safety factor are combined into a single and integrated objective function, and Kriging interpolation is then used to create the surrogate model of the integrated objective function. When the integrating optimization procedure is used, the integrated objective function demonstrates that the von Mises stress for the optimized handlebar stem is reduced to 225 MPa and the fatigue safety factor increases to 1.796. This shows that the optimized design increases the strength of the handlebar stem. The proposed technique yields a handlebar stem with an optimized shape.


2021 ◽  
Author(s):  
Malcolm A Goodman

Abstract The API equation for internal leak of API connections is uniaxial since it ignores axial force and external backup pressure. ISO 13679 for qualification of premium connections is biaxial at best. It includes tension/compression but ignores backup pressure for both internal and external leak tests. For tubular design, this paper introduces a new fully triaxial safety factor for threaded connections with dependence on thread shear and hydrostatic pressure. Hydrostatic behavior is modelled with the Mean Normal Stress, and thread shear behavior is modelled with the shear component of the von Mises Stress. A Leak Line for use like the pipe body ellipse is proposed for quick leak assessment. Leak ratings are presented for an example case of 7-in. 35-ppf N80 LTC. The new triaxial safety factor with two connection constants applies to all types of threaded connections, including tubing, casing, and drill pipe, so long as the two constants are evaluated with appropriate but simple physical tests.


2021 ◽  
pp. 1-11
Author(s):  
Malcolm A. Goodman

Summary The American Petroleum Institute (API) equation for internal leak of API connections is uniaxial because it ignores axial force and external backup pressure. The ISO 13679 (2002) standard for qualification of premium connections is biaxial at best. It includes tension/compression but ignores backup pressure for both internal and external leak tests. For tubular design, this paper introduces a new fully triaxial safety factor for threaded connections with dependence on thread shear and hydrostatic pressure. Triaxial hydrostatic behavior is modeled with the mean normal stress, and thread shear behavior is modeled with the shear component of the von Mises stress. A leak line for use like the pipe body ellipse is proposed for quick leak assessment. Leak ratings and correlation with finite element analysis (FEA) results are presented for an example case of a 7-in.35-ppf N80 long-thread-casing (LTC) connection. The new triaxial safety factor with two connection constants applies to all types of threaded connections, including tubing, casing, and drillpipe, so long as the two constants are evaluated with appropriate but simple physical tests.


2013 ◽  
Vol 482 ◽  
pp. 297-301
Author(s):  
Lin Sun ◽  
Fu Ting Bao ◽  
Wei Shi ◽  
Hao Xu

A coupled fluid, thermal and structure analysis model was established for solid rocket motor nozzle. Based on a steady flow simulation and a transient thermal simulation, a transient structure analysis simulation was executed. The model took a frictional coefficient 0.3 into account to simulate a rub action between the parts of the nozzle. Result showed that with a frictional coefficient, Von Mises stress could be released which gives a constructive recommendation for a structure simulation of a nozzle. Also, the model was more close to the actual. A more dependable approach was introduced and it could contribute to designing department.


2019 ◽  
Vol 16 (03) ◽  
pp. 1842006 ◽  
Author(s):  
Xinyang Cui ◽  
Qingshuai Ren ◽  
Gaoyang Li ◽  
Zihao Li ◽  
Aike Qiao

The stents’ adaptability and safety in realistic and idealized stenotic coronary model were compared to investigate the influence of artery geometry parameter on stent fatigue life. The stents’ fatigue resistance ability was calculated using Goodman diagram, and the cycle to failure, the fatigue life, and the fatigue safety factor (FSF) were analyzed. Although the peak top of the von Mises stress was located at the bending area of crowns, the stress distributions were different in the two models. Considering the safety and accuracy, it is necessary to use a realistic geometric model to calculate the stent fatigue performance.


2021 ◽  
Vol 26 (1) ◽  
pp. 69-78
Author(s):  
Aji Abdillah Kharisma ◽  
Ahmad Fadel Givari ◽  
Irvan Septyan Mulyana

Storage tank adalah alat yang dibutuhkan dalam industri minyak bumi dan gas. Fungsi dari storage tank ialah untuk menyimpan fluida dalam jumlah yang besar. Tangki timbun harus memiliki dinding yang kuat untuk menahan suatu tekanan, maka tangki tersebut tidak mengalami kerusakan. Penelitian ini membahas tentang kekuatan desain fire water storage tank, dari kriteria faktor keamanan, von misses, dan displacement. Metode yang digunakan adalah metode perhitungan actual dan metode analysis simulasi (analysis simulation). Data input desain shell diberi internal pressure sebesar (1 atm) atau (0,101325 MPa), pada hasil simulasi solidworks didapatkan nilai dari von mises stress sebesar (150,49 MPa), safety factor (1,36), dan displacement (5,95 mm). Hasil metode perhitungan aktual didapatkan nilai von mises sebesar (155,245 MPa), safety factor (1,32), dan displacement (4,274 mm). Berdasarkan hasil analisa desain dari storage tank dapat dinyatakan aman digunakan dikarenakan nilai von mises berada dibawah nilai yield strength (205 MPa), safety factor berada pada kisaran (1-10), serta displacement yang tidak terlalu signifikan.


2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Sugiarmadji ◽  
Setiadi

Structural strength analysis on Motor Rocket-168 fins was carried out to determine static stresses due to aerodynamic loadings. Here, 90 mm of the root chord area from leading edge was unclamp (free). The analysis results showed the maximum value of von Mises stress is Q von mises = 42.40 MPa. For 90 mm condition un clamp (free) we obtained the safety factor of the material for fins structures made of Al-Plate is SF=3.39. For 67.5 mm of 90 mm root chord area constrainted at 12456 directions, it was found Qvm equal 11,26 MPa and has higher safety factor. Eigenvalues and eigenvectors of the fins structures. The results showed that the eigenvalues of the fin structures are Q1 equal 198,47 Hz, Q2 equal 616,34 Hz, Q3 equal 1080,97 Hz, Q4 equal 1704,33 Hz, Q5 equal 2386,82 Hz, dan Q6 equal 2770,94 Hz.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Lasinta Ari Nendra Wibawa

The rocket motor is an important part of rockets. The rocket motor works using the pressure vessel principle because it works in an environment with high pressure and temperature. This paper investigates the von Mises stress that occurs in thin-walled cylinders and safety factors for rocket motor cases due to the influence of the wall thickness and internal pressure. Dimensions of the cylinder length are 500 mm, outer diameter is 200 mm, and cap thickness is 30 mm. The wall thickness is varied 6, 7, 8, and 9 mm, while the internal pressure is varied 8, 9, and 10 MPa. Stress analysis is performed using the finite element method with Ansys Workbench 2019 R3 software. The simulation results show that the maximum von Mises stress decreases with increasing wall thickness. The maximum von Mises stress increases with increasing internal pressure. The material has a safety factor higher than 1.25 for all variations in wall thickness and internal pressure. It means that the material can withstand static loads. The verification process is done by comparing the results of finite element analysis with analytical calculations for maximum hoop stress and maximum axial stress with a fixed boundary condition. The results of maximum hoop stress and maximum axial stress using finite element analysis and analytical calculations are not significantly different. The percentage of errors between analytical calculations and finite element analysis is less than 6 percent.


2020 ◽  
Vol 2 (2) ◽  
pp. 1
Author(s):  
Mohammad Ihya’ Ulumuddin

Plastik merupakan salah satu bahan baku untuk membuat suatu product plastik yang berguna untuk memenuhi kebutuhan manusia, Selama  pengamatan di PT X terutama dalam proses pembuatan desain molding, di tempat tersebut tidak melakukan analisis desain menggunakan software, oleh sebab itu penulis membuat analisis molding menggunakan software, penelitian ini bertujuan menganalisis kekuatan plate insert cavity pada saat mendapatkan tekanan 160 MPa dari mesin injection untuk mengetahui tegangannya perlu dilakukan analisis memakai software autodesk inventor profesioanl 2017 Pada analisis ini dilakukan studi langsung di PT X Proses analisis diawali dengan membuat desain 3D molding kemudian masuk ke menu stress analysis pada kotak dialog pressure dimasukan data tekanan yang sebesar 160 Mpa, untuk bahan molding yang digunakan untuk analisis adalah stainless steel, setelah data masuk semua bisa langsung dijalankan simulation tegangannya, dari analisis akan diperoleh data tegangan seperti von misess, stress, strain, displacment, .dan safety factor Berdasarkan hasil analisis statis didapat kekuatan molding yaitu nilai von mises stress maksimum adalah 124,2  Mpa, nilai Stress maksimum adalah 118,1 Mpa, nilai displacement maksimum adalah 0,06579 mm, , nilai strain maksimum adalah 6,03 x 10-4, dengan nilai faktor keamanan 2,01 maka faktor kemanan beban pada molding masih aman mengunakan bahan stainless steel.


Author(s):  
Ricardo M. Amé ◽  
Gabriel M. Dasso

Due to its functional characteristics, machine components are designed with various geometrical discontinuities, usually combined in a single section or sections very close. Localized stresses they generate are difficult to obtain if not by computer. The classical literature offers no stress concentration factors for cases as common as those seen in, for example, the design of a shaft, where they coexist, with various geometric discontinuities, efforts as torque and bending combined. In this work we present and analyze the results obtained from the Von Mises stress occurring in areas of a shaft with a change in diameter and a keyway, considering the load applied as a lateral pressure from the key generated to transmit a given torque. It is also considered a bending effort. The objective is to obtain the Von Mises stress values for different positions of the keyway with respect to the fillet radius for the change in diameters and also to find the influence of the proximity of the keyway on the values of the stress in the fillet radius.


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