Group Design Project Poster

1. Development of drop tower
experimental facility
Individual poster of Adrian Azorin Albero
Teammates: David Andrés, Hugo Gallet, Agnieszka
Krupinska, Hakim Masyhur, Aurélien Royer, Ibai Unanue
Supervisors:
Dr James Campbell
Dr Tom de Vuyst
Technical
contributions
External frame load case analysis
FE modelling of indentation test
MSc Advanced Lightweight Structures and Impact 2013-2014 Group Design Project
Offset 𝑑𝑑 of
𝟏𝟏. 𝟗𝟗𝟗𝟗𝟗𝟗 assumed
at the point of
impact 𝑅𝑅𝑅𝑅 = 𝟏𝟏. 𝟔𝟔𝟔𝟔
• Design of the frame, shafts and bearings
• FEA: Indentation test analysis (High weight impact)
• FEA: Study of the operating range when the sample is located at the centre
Equivalent static
load of 𝟖𝟖𝟖𝟖𝟖𝟖𝟖𝟖
applied on the
trolley
𝑀𝑀 = 𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏
(Applied on the bearings)
Buckling analysis
Objective: Estimate the
buckling load of the beams
attached to the shafts
assuming imperfections
𝒇𝒇𝒏𝒏 (MPa) 130
𝑬𝑬 (GPa) 72
𝒎𝒎 (-) 20
𝑨𝑨 (m2
) 0.00183
𝑰𝑰𝒙𝒙𝒙𝒙 (m4
) 124.4 x 10-8
𝑳𝑳 (m) 3
𝒛𝒛 𝒎𝒎𝒎𝒎𝒎𝒎 (m) 0.04
ESDU 01.01.01 𝑷𝑷𝒄𝒄𝒄𝒄 = 𝟏𝟏𝟏𝟏𝟏𝟏. 𝟗𝟗𝟗𝟗𝟗𝟗𝟗𝟗𝟗𝟗
Support frame Sample plate
Hemispherical indenter
• FS=0.3 Indenter-Plate
• FS=0.2 Support Frame-Plate
Dry conditions assumed:
FE Results for dry conditions (Friction)
Force (kN) Deflection (mm) Energy (J)
7.72 11.1 54.6
Experimental Results: Force: 9.7 kN, Deflection: 13.1 mm, Energy: 61.9 J [1]
Better FE prediction
obtained assuming
dry conditions
FE analysis of crushing tube experiment (lighter trolley with sample at the centre)
40x40mm square hollow tube 0.6mm thick
walls
Part RF
I-Beam (Trolley) 9.8
Flat plate (Trolley) 7.9
Support plate 41.5
Support frame 51.9
External frame 8.9
Interaction between
trolley and shafts
through the contact
guided cable
algorithm used for
the mounting
modelling
Accelerometer’s data extraction
Accelerometer FE model
*ELEMENT_SEATBELT_ACCELEROMETER
Accelerometer
Low-pass filter with a minimum cut-off
frequency of 41.84Hz is required in order to
extract the fundamental acceleration pulse
[1] Liu B., Villavivencio R., Guedes Soares C. (2013), Shear and tensile failure of thin aluminium plates struck by cylindrical and spherical indenters, Analysis and Design of Marine Structures.
Contact: a.azorinalbero@cranfield.ac.uk
𝑰𝑰𝒙𝒙, 𝑰𝑰𝒚𝒚 (cm4
) 124.4
𝝈𝝈𝒚𝒚 (MPa) 110
𝑬𝑬 (GPa) 72
Sample plate:
2mm thickness
5083/H111 aluminium
alloy
Support frame:
15mm thickness
2 rectangular steel plates
Internal cut-out of 127 x 76.2 mm
Crashworthiness, Impacts and Structural
Mechanics Group (CISM)
Beam
imperfection
assumed:
𝒆𝒆 = 𝟎𝟎. 𝟎𝟎𝟎𝟎𝟎𝟎𝟎𝟎
[1]
Operating limit:
• Tube thickness: 1.1mm
• Peak force: 12kN
No Frame: Independent trolley model
Reason:
Mass: 24.3kg
Impact velocity: 4.5m/s
K.E.: 250J
Mass: 4.901kg
Impact velocity: 5.4m/s
K.E.: 71.42J
• FEA: Modelling of indentation test
• FEA: Assembly of the finite elements model with the lighter trolley
• Study of the accelerometer’s data extraction and FE model implementation
Methodology: Define a
critical load case at the
moment of impact.
Identify the most critical
point which determines
how the frame is sized by
drawing free body
diagrams for all
structural components
Section choice
Objective: Develop and
validate a finite elements
model to be implemented
in the whole tower model
for studying the overall
structural behaviour of the
system when performing
this experiment
Objective: Check
the design of the
drop test tower
with the lighter
trolley and define
the operating
range. The table
shows the reserve
factors obtained
when crushing the
0.6mm tube
Objective: Implement an
accelerometer FE model in
the whole tower model and
define a methodology for
being able to filter the high
frequency content obtained
when performing drop tests.
These results help calibrate
the tower
The accelerometer FE model created was
implemented in the whole tower FE model with
the lighter trolley. The required low-pass filter
was calculated by analysing the results obtained
for the crushing tube located at the centre