Department of Civil Engineering
National Institute of Technology (KOSEN), Akashi College

Studies on the ultimate strength of several structures
NameMIYOSHI Takao

StatusProfessor

Affiliations
Keywords

E-mailmiyoshi@akashi.ac.jp

JSCE (Japan Society of Civil Engineers), JSSC (Japanese Society of Steel Construction),
JSME (The Japan Society of Mechanical Engineers)

structures, ultimate strength, finite element method, artificial intelligence
Ultimate strength evaluation of several structures based on non-linear finite element method

TechnicalSupport Skills

Finite element method program development for estimating ultimate strength evaluation
Ultimate strength evaluation of steel structures based on model testing
Application of artificial intelligence to the ultimate strength evaluation on several structures

Research Contents(1) Redundancy evaluation of the steel bridge due to its member failure and volume loss by using non-linear finite element method(2) Exploitation of finite element simulation method which is able to model partial volume loss of steel plate with the element elimination(3) Strength test using model specimen with volume loss of the steel structure(4) Mechanical properties estimation of structural stainless steel required for constructing constitutive equation using machine learning

Verification analysis of steel truss bridge redundancy due to break of lower chordmember(Axial force is transmitted from broken lower chord member to the opposite side ofthe chord.)60

β = 50%β = 0%

β = 100%

Main girder end specimen of H-beam bridge with several volume loss
rates β after compression test
(In case of specimens with β = 50, 100%, significant out-of-plane
displacement tends to occur near the cross-section including volume loss
portion, because compressive stress increase in the portion.)50

Error = 0%
Error = 10%
Error = 20%

0.830
Theoretical
Reduced integration
Full integration
Three-division
Six-division

2010(σ0.2/σu)test

Volme loss rate (%)

140

Error = -10%
Error = -20%

0.6

Austenitic (Eq.)
Austenitic (RF)
Duplex (Eq.)
Duplex (RF)
Ferritic (Eq.)
Ferritic (RF)

0.4

000.5
1
1.5
2Transverse displacemen δA (mm)

0.2
0.2

Cantilever steel plate progressing partial volume loss on its front and rear surfaces undercompression(20 nodes solid elements are applied to partial volume loss area on front and surfaces ofthe plate by dividing 1-6 layers. Partial volume loss is introduced by eliminating theelements. In case of 1 divide model, reduced integration is carried out as well. Numericalresults between volume loss rate and transverse displacement at the tip of the plate aregood agreement with the result by beam theory regardless of element divisions.)

0.4

0.6
0.8(σ0.2/σu)prediction

11.2

0.2% proof stress estimation of austenitic, duplex and ferritic
stainless steels by using Random Forest as one of machinelearning method and their prediction equations(Predicted value by Random Forest shows high accuracy incomparison with that by prediction equation)

Available Facilities and Equipment
Universal hydraulic testing machine (2000kN capacity)

General purpose finite element analysis program MSC Marc/Mentat

Personal computer （Dell Precision 3640）

Self-made non-linear finite element analysis program

Personal computer （Be-Clia）

Exterior digital caliper gauge (TECLOCK GMD-1J)

Intel Fortran compiler

Digital point micrometer (Niigata Seiki MCD232-25P)

General purpose pre and post processor GiD

Portable Data Logger (TML TDS-150)