Department of Aerospace Engineering

Smart Systems for Materials and Structures
Okabe, Kawagoe,Nagumo & RyuzonoLab.
【Multiscale Modeling Strategy】【Airport Surface Traffic Flow Analysis】“Atom“AtomstotoAircraft”
Aircraft”

Quantum
Mechanics

MolecularDynamics

Finite Element
Micromechanics

Component
Strength, Life, Reliability…

Air traffic management simulation
N➢Electrons[Å]

Finite Element
Laminate Analysis

35.57
Composite strength
Homogenized constitutive law

RW34R

35.56
Latitude

Atoms
[nm]

Matrix properties
Cohesive traction versus

Curing reaction property

1535.54

10RW05【Multidisciplinary Design Optimization of Composite
Aircraft Wing】
Aerodynamic/structural analysis

5RW34L

35.52
139.76 139.78 139.8 139.82
Longitude

Flight data around Haneda Airport

252035.55

35.53

Carbon fiber-reinforced plastic (CFRP) composites are widely used inengineering products including aircraft. CFRP has a characteristichierarchy since it consists of fibers with micron-scale diameters andmatrix. Therefore, multiscale simulations are essential for design andreliability of the CFRP products.

30Taxing speed [kt]Multipleplies[mm]

Fiber/Matrix
Phase separation[µm]

Engineering
design[m]0Flight data analysis

The global air traffic is expected to increase in the future, and in order tocope with this, optimization of operations, especially at airports andsurrounding airspace, is required. In this study, the characteristics of air
traffic flow are obtained from flight data, and based on the results, thedominant factors of air traffic flow on the airport surface of Haneda
Airport are clarified by numerical analysis, and the optimal management
method is investigated.

【 Numerical Simulation of Progressive Damage in CFRP】
DTransverse crack

00.450.9Shape optimization
The application of CFRP to aircraft, such as the B787, has been
expanding rapidly in recent years. In this study, the Multidisciplinary
Design Optimization (MDO) method coupled with fluid and structural
analysis is proposed for the optimum design of the shape and internal
structure of composite aircraft wings.

Fig.1 Crack Initiation
Experiment【Molecular Dynamics Simulation of Epoxy Resin】
88% Peak Load

Simulation cell

90% Peak Load

99% Peak Load

Peak Load

Simulation：H：C：N：O：S

89% Peak Load

95% Peak Load

Peak Load

Fig.2 Open hole compression test
BeforeTransition state

After

Base resin
Curing agent
Reaction

Reaction

Thermoset resin, which is commonly used as a matrix in CFRP, consistsof a base resin and a curing agent, which form crosslinking networks via
chemical reactions. This study analyzes the curing process of thermoset
resins by using molecular dynamics simulation and investigates the curing
characteristics and mechanical properties of resins.

◇ Crack initiation in CFRP laminate (Fig.1)
Transverse crack is the initial failure of composite structures, and thestrain where those cracks are generated is often used in the design
criteria. In order to verify the structural reliability, multiscale analysis forthe initiation of transverse cracking in cross-ply laminates is conductedusing the periodic unit cell (PUC) analysis.
◇Open-hole compressive (OHC) strength of CFRP laminate (Fig. 2)
Open-hole strength is important because CFRP members with holes
are riveted in the aircraft body. This study will develop a numericalanalysis method that can reproduce the OHC test with high accuracy
and contribute to cost reduction related to aircraft certification.