Short, J-section columns fabricated from a textile composite are tested in axial compression to study the modes of failure with and without local buckling occuring.The textile preform architecture is a 2x2, 2-D triaxial braid with a yarn layup of [0 deg 18k/+-64 deg 6k] 39.7% axial. The preform was resin transfer molded with 3M PR500 epoxy resin. Finite element analyses (FEA) of the test specimens are conducted to assess intra- and inter- laminar progressive failure models. These progressive failure models are then implemented in a FEA of a circular fuselage frame of the same cross section and material for which test data was available. This circular frame test article had a nominal radius of 120 inches, a forty-eight degree included angle, and was subjected to a quasi-static, radially inward load, which represented a crash type loading of the frame. The short column test specimens were cut from some of the fuselage frames. The branched shell finite element model of the frame included geometric nonlinearity and contact of the load platen of the testing machine with the frame. Intralaminar progressive failure is based on a maximum in-plane stress failure criterion followed by a moduli degradation scheme. Interlaminar progressive failure was implemented using an interface finite element to model delamination initiation and the progression of delamination cracks. Inclusion of both the intra- and inter- laminar progressive failure models in the FEA of the frame correlated reasonably well with the load-displacement response from the test through several major failure events. / Master of Science

In recent years, the use of computer-aided design (CAD) systems for conceptual aircraft design has greatly increased. As a result, new and better methods for creating surface models of aircraft geometry using dimensional parameters are needed. One such method, the Rule-Based Fuselage method, was suggested by Lockheed. The Rule-Based Fuselage method allows an aircraft designer to define complex aircraft fuselage geometry by specifying the fuselage profile and individual parametric cross-sections along the fuselage. This thesis describes the Rule-Based Fuselage method and discusses the implementation of the method in an interactive, object-oriented environment. Also included in this system is the Spine and Cross-Section method for creating arbitrarily shaped aircraft components. The design and implementation of both the Rule-Based Fuselage and Spine and Cross-Section methods are described. The integration of these methods with the conceptual aircraft design code, ACSYNT, is also discussed. / Master of Science

Bibliography : leaves 237-251. / x, 251 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1994

Statistical Energy Analysis (SEA) is one of the methods in literature to estimate high frequency vibrations. The inputs required for the SEA power balance equations are damping and coupling loss factors, input powers to the subsystems. In this study, the coupling loss factors are derived for two and three plates joined with a stiffener system. Simple formulas given in the literature for coupling loss factors of basic junctions are not used and the factors are calculated from the expressions derived in this study. The stiffener is modelled as line mass, Euler beam, and open section channel having double and triple coupling. Plate is modelled as Kirchoff plate. In the classical SEA approach the joint beam is modelled as another subsystem. In this study, the beam is not a separate subsystem but is used as the characteristics of the joint and to calculate the coupling loss factor between coupled plates. Sensitivity of coupling loss factors to system parameters is studied for different beam approaches. The derived coupling loss factors and input powers are used to calculate the subsystem energies by SEA. The last plate is joined to the first one to simulate the fuselage structure. A plate representing floor structure and acoustic volume are also added. The different modelling types are assessed by applying pressure wave excitation. It is shown that deriving the parameters as given in this study increases the efficiency of the SEA method.

The thesis is focused on reconstruction of middle part of fuselage Z 143 aircraft from truss frame to semi-monocoque frame. In the thesis there is a conceptual design of semi-monocoque middle part of fuselage. The spars of centre wing section are strength controlled. In thesis there is weight analysis according to use the semi-monocoque middle part of fuselage. In second half of the thesis there is a study of retractable landing gear. The thesis shows weight savings according to use a semi-monocoque frame. The thesis also shows that semi-monocoque frame allows other option to upgrade Z 143 aircraft. This thesis can serve as a feasibility study of the reconstruction of the middle part of the fuselage Z 143 aircraft.

ploma thesis deals with design of a four-seat sport aircraft for basic training, tourist flying and glider towing, which can be used in aeroclubs and by private owners. The objective of this thesis was to design the outer shapes of the aircraft, compute the basic aerodynamic characteristics and performance, design of structural and aerodynamic layout of the wing and design of flap system with governing.

The object of diploma thesis is a loading determination for strength calculation of HPH 2 Twin Shark glider matching the requirements of Certification Specification for Sailplanes (CS-22). Loading of the wing, tail section, fuselage and undercarriage is determined in this work.

This thesis deals with CFD analysis of a wing-fuselage junction on L410NG airplane. Possible modifications are proposed as well. Calibration problem solved in the introduction serves as a pathway for validation of the results and gives insight into the CFD methodology. The main part analyses the airplane's flow field and shows the details of the modelling process. Description of the computing network followed by final evaluation is presented. Next part is devoted to the creation and aerodynamic analysis of the modified geometry. Final part of the work compares both basic and modified geometry.

This master’s thesis deals with VUT 081 Kondor composite fuselage design and control system layout design. Load computation and selection of critical load cases are made. Principal inner surfaces of the fuselage are designed with respect to basic ergonomic requirements of the crew. Construction materials are chosen and a layup of composite materials is performed. Fuselage FEM model is made in MSC Patran/Nastran system and the structure-strength analysis is given for chosen load cases.

Aircraft structural layout concept design at Saab Aeronautics utilize thickness optimizationto evaluate astructural layout concept. The thickness values can be used to compare conceptsto each other,and the bestonecan be further developed. Today, most ofthe creation and evaluation of structural layout concepts is manual work. Therefore, there is an ongoing investigation on how to implement design automation to reduce this manual and repetitive work. The investigationaims to achieve rapid exploration of the design space to find a good base for a new aircraft development. This includes investigating how the synchronization between a structural layout model (SLM) and a global finite element model (GFEM) can be improved. This thesis contributes to the investigation by exploring the possibilities to implement design automation in the creation of the SLM regarding the fuselage structure. Further, exploring the implementation of design automation in the creation of the GFEM to enable automatic evaluation of concepts. The thesis also explores how the synchronization between the models can be improved. To structure the thesis work, the software development methodologies of MOKA and RAD weremodified and combined. The execution of the thesis was carried out in the software of 3DEXPERIENCE, particularly using the applications CATIAand SIMULIA. This thesis work resulted in a methodfor developing and evaluating aircraft structure concept designs with design automation. The new method includes two models with corresponding scripts. The first model developed is a tool for a conceptualdesignerthat enables the creation of aircraft fuselage SLM from user defined inputs. The second model is generated by script which results in a GFEM with a direct connection to the SLM. To conclude, the developed method enables a faster iteration work of fuselage structural concept designs compared to the current method. The detail level is lower but more consistent and uniform. The GFEM was not able to fulfil its purpose in the developed method due to time limits and software limitations. However, the synchronization between the SLM and GFEM was implemented successfully and contained all critical elements.