A probabilistic design analysis approach for launch systems

1991 ◽  
Author(s):  
FAYSSAL SAFIE ◽  
ERIC FOX
Keyword(s):  
Design Analysis ◽  
Analysis Approach ◽  
Probabilistic Design ◽  
Launch Systems

scholarly journals Preliminary Sizing of a Medium Range Blended Wing-Body using a Multidisciplinary Design Analysis Approach

2018 ◽  
Vol 233 ◽  
pp. 00014 ◽  
Author(s):  
Alessandro Sgueglia ◽  
Peter Schmollgruber ◽  
Emmanuel Benard ◽  
Nathalie Bartoli ◽  
Joseph Morlier
Keyword(s):  
Fuel Consumption ◽  
Aircraft Design ◽  
Design Analysis ◽  
Multidisciplinary Design ◽  
Analysis Approach ◽  
Medium Range ◽  
Blended Wing Body ◽  
Reduce Emissions

The aviation's goal for the next decades is to drastically reduce emissions, but to achieve this goal a breakdown in aircraft design has to be considered. One of the most promising concepts is the Blended Wing- Body, which integrates aerodynamics, propulsion and structure, and has a better aerodynamics efficiency, thanks to the reduction of the wetted surfaces. In this work the feasibility of a short/medium range BWB with 150 passengers (A320 Neo type aircraft, Entry Into Service 2035) is studied, considering different disciplines into the sizing process. The design loop has been reviewed to consider the unconventional concept. Also certification aspects have been taken into account in an off-design analysis. To evaluate the advantages of the proposed concept, it has been compared with an aircraft of the same class, the A320 Neo, resized to match the EIS2035 hypothesis: results show that the BWB is a concept that demonstrates a gain in fuel consumption, especially on longer ranges.

A Design Analysis Approach for Improving the Stability of Dynamic Systems with Application to the Design of Car-Trailer Systems

2005 ◽  
Vol 11 (12) ◽  
pp. 1487-1509 ◽  
Author(s):  
Y. He ◽  
H. Elmaraghy ◽  
W. Elmaraghy
Keyword(s):  
Dynamic Systems ◽  
Stability Criterion ◽  
Degrees Of Freedom ◽  
Integrated Approach ◽  
Design Analysis ◽  
Analysis Approach ◽  
Dynamic Mode ◽  
Stability Characteristic ◽  
Design Variables ◽  
The Stability

A design analysis approach is developed for improving the stability of dynamic systems subject to non-conservative forces. It combines genetic algorithms, sequential quadratic programming (SQP), and dynamic mode tracking (DMT). The proposed approach automatically optimizes the stability criterion and is applicable to rotor dynamics, wind turbine dynamics, aeronautics, and ground vehicle dynamics. The Routh-Hurwitz criterion has traditionally been used for determining the stability characteristics of these dynamic systems. In the conventional trial and error approaches, designers iteratively change the values of the design variables and reanalyze until an acceptable stability characteristic is achieved. This is both time-consuming and tedious. The proposed approach automates the design/analysis cycle by using the DMT technique to identify the modes; then, the SQP algorithm determines the stability criterion; and finally a genetic algorithm is applied to optimize design variables. The proposed integrated approach has been tested and evaluated numerically using a linearized car-trailer model with three degrees of freedom and the results demonstrate its feasibility and efficacy. The performed parametric sensitivity analysis revealed that the geometric parameters have a much greater influence on the lateral stability of the vehicle systems, compared with inertia parameters and torsional spring stiffness coefficients.

The improvement of assembly process and environmental impact using the integration of DFMA and sustainable design analysis approach: Case study of spotlight

2021 ◽  
Author(s):  
M. S. M. Effendi ◽  
Z. Shayfull ◽  
H. Radhwan ◽  
Shafeeq Ahmad Shamim Ahmad ◽  
Muhammad Mustaqim Muslim ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Sustainable Design ◽  
Design Analysis ◽  
Analysis Approach ◽  
Assembly Process

Integrity Assessment of Interaction of Dents With Residual Stresses of Welds Using Probabilistic Design Analysis

2012 ◽  
Author(s):  
Husain Mohammed Al-Muslim ◽  
A. F. M. Arif
Keyword(s):  
Residual Stresses ◽  
Weld Line ◽  
Design Analysis ◽  
Probabilistic Design ◽  
Stress Range ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Girth Welds ◽  
Longitudinal Welds ◽  
The Impact

The interaction of dent with the weld has always been considered a threat to the pipeline. Therefore, Codes and procedure impose more stringent rules than normally applied to plain dents. For example, ASME B31.8 considers dents deeper than 2% and interacting with welds to be injurious and requires an engineering assessment if they are to be left without repair. The objective of this paper is to present a new method of assessment that utilizes finite element analysis couples with probabilistic design analysis. In this paper, the impact of interaction of dent with longitudinal welds and girth welds will be under static and cyclic pressure conditions will be evaluated. The combined effects are included in a single FEA model and the welds will be simulated by imposing initial residual stresses along the weld line. The first part of the paper uses deterministic analysis to present strain and stress contours at the end of indentation stage as well as the stress range and fatigue cycles at the end of pressure cycle stage for a longitudinal weld case as well as girth weld case. The second part uses probabilistic design analysis with variable geometry, material and pressure in addition to the weld location and residual stress value to determine the sensitivity of the strain, stress, and stress range to the input. Two probabilistic design analyses are conducted: one for the interaction of dent with longitudinal welds, the other for the interaction of dent with girth welds.

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