1 / 11

Research Project: Investigation on material mechanical behaviour finalized to improve numerical analyses of impacts on a

Research Project: Investigation on material mechanical behaviour finalized to improve numerical analyses of impacts on aircraft structures Andrea Gilioli 04/03/2011. Motivations. Impact against aircraft structures could generate severe structural damages. High velocity.

noura
Download Presentation

Research Project: Investigation on material mechanical behaviour finalized to improve numerical analyses of impacts on a

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Research Project: Investigation on material mechanical behaviour finalized to improve numerical analyses of impacts on aircraft structures Andrea Gilioli 04/03/2011

  2. Motivations Impact againstaircraftstructurescouldgenerate severe structuraldamages High velocity In order to improvesafety,numericalsimulation can be usefull to evaluate the structuralintegrity Low velocity Reliablenumericalsimulationsneed a goodcalibration of the mechanicalbehaviour of the material

  3. Main object of research:from experiment to FE simulations Experimental tests Main object of research: Improving these phases in order to get more reliable numerical results Constitutive law calibration VIRTUAL TESTING APPROACH Damage criterion calibration FE simulations of experimental tests (tensile, upsetting, torque, TPBT, multiaxial) to calibrate material properties Numerical simulation of ballistic impact

  4. Material damage:real applications Technological process Failure events Materialdamage Ballistic impact Forging Permanent and irreversible modification of material: expected (technological process) or not expected (failure events) Bird impact Trenching Drawing Crash

  5. Material damage:focus on aircrafts • Response of aircraft components to impacts • Technological process • Improving process efficiency • ballistic • bird • Main focus of research • Why study material damage? • crash • Failure events • Improving safety Increasing safety Specific aircraft point of view Decreasing weight

  6. Very complex phenomenon Numerical models (FE) • Involves a great number of parameters • Expensive and difficult experimental tests • Analytical model only for very simplified problems High velocity Impactatorerosion Target perforation IMPACT Friction High plasticstrains Heat generation • Numerical analysis are fundamental

  7. Aircraft materials • Aircraft manufacturing materials are various: • Metals (steel, aluminum, titanium alloy,…) • Composite (sandwich panels,…) • Material failure is a very complex physical phenomenon: • it’s different for each kind of materials (metals, plastics, composite,…) • change for the same materials depending on load conditions and geometry. A unique approach in order to numerical modeling all these different materials appears unrealistic. Instead a global systematic approach aim at the development of a rigorous procedure to obtain material properties to insert in FE analysis is very interesting.

  8. Research objectives and motivations OBJECTIVES MOTIVATIONS • FE analysis are always more frequent in order to: • Reduce experimental cost and related difficulties • Improving safety • Improving performance (weight reduction) • Material data are fundamental to get reliable numerical results • Development of a global approach procedure to calibrate mechanical behavior (including failure) of most common aircraft materials • Focus on FE simulation of the most catastrophic events for aircraft (ballistic impact, crash) • Validation with the comparison between FE results and real ballistic experiment on aircraft components (mast, shaft, hub, frame)

  9. Possible improvements of current state of art IMPROVEMENTS • Develop of a systematic procedure to identify material properties could guarantee more reliability of following FE simulations of complex and extreme scenarios (i.e. ballistic impact) • Improve helicopter safety: • Design of better ballistic protections (improving withstanding against impacts, lighter) • Better evaluation of structural integrity of helicopter damage components (i.e. mast, shaft, hub, frame) due ballistic impacts or crash events, improving following damage tolerant analysis • General cost reduction (less experimental tests, more reliable data for design phase) • Easiness to extend results to a wide range of applications such as general transportation field (train, car crash), military field (ballistic and explosions protections), general civil machinery protection, plastic deformation technological process,…

  10. Time scheduling • First year: • Bibliographical review • Aircraft\helicopters materials • Damage criteria • Experimental test • Develop of preliminary logical scheme of calibration process • Second year: • Experimental calibration of materials (tensile, upsetting, torque, multi axial, three point bending) • Development of FE virtual test models to simulate experiments • Calibration of materials • Third year: • Experimental ballistic test on aircraft components (mast, shaft, hub, frame) • Development FE models describing impact • Validation of result FE\experimental OBJECTIVES

  11. Work Plan 11 Main courses Elective courses and training on specific themes

More Related