The Department of Joining Mechanics and Analyses is dedicated to solving manufacturing and application problems of welded and joined structures, in which multi-physics phenomena involving heat transfer, material flow, microstructure evolution, and mechanics in welding, joining, and metal additive manufacturing processes are analyzed through numerical simulation based on mathematical modeling, AI, and computational mechanics.
In particular, the Department is promoting advanced computational technologies for next-generation digital manufacturing through FSW and machining process analysis using the Eulerian approach, thermo-elasto-plastic analysis using adaptive local remeshing techniques, metal additive manufacturing process analysis, and hot cracking simulation. The division is also engaged in applied research for shipbuilding and large-scale structures, including thermal distortion prediction using AI, machine learning and digital twin technologies, optimization of assembly sequences, and smart forming of ship hull plates using autonomous line heating robots.
With the aid of Idealized Explicit FEM, AI-integrated thermo-elasto-plastic simulation technologies, and advanced measurement techniques developed in the department, distortion, residual stress, and structural integrity of various welded and joined structures are accurately predicted in order to realize highly efficient and highly reliable smart manufacturing technologies.

Muti-physics simulation of FSW and cutting by Eulerian approach

Development of AI Line Heating Robots for Smart Forming

Multiscale Thermo-Elasto-Plastic Analysis Using Adaptive Local Remeshing Techniques

Prediction of Thermal Distortion and Residual Stress in Metal AM Processes

Development of a High-Fidelity Multiphysics Simulation Method for Hot Cracking

Development of AI- and Digital Twin-Driven Thermo-Elasto-Plastic Simulation Technology

Members

Prof.

M. SHIBAHARA

Assoc. Prof.

K. IKUSHIMA

S. Assoc. Prof.

R. GADALLAH

S. Assoc. Prof.

Y. TAKEMOTO

S. Lecturer

S. MAEDA

S. Asst. Prof.

T. Kato

S. A. Researcher

A. KAWAHARA

In this research division, the structural design and fabrication processes are considered on the following two aspects: the "through-process" and "trans-scale." The concept of "through-process" considers the time axis throughout the life cycle, from the design and construction process, such as welding and joining, to testing, service, repair, reinforcement, and maintenance. The concept of "trans-scale" considers spatial axes ranging from micro to macro, such as the microstructure of materials of welds, welding and joining components, and structures.
We research the evaluation of the performance and reliability of various structures at each of these stages and scales. In particular, the effects of thermal processing, represented by residual stresses and deformations, on the performance of welded and joined components and structures will be clarified from both microscopic and macroscopic perspectives. We will also develop a detailed and intelligent evaluation method based on these findings. Our goal is to establish design engineering that contributes to the advancement of structuring processes such as welding and joining.

Simulation technique for joint characteristics considering weld residual stress and effects of fabrication and loading

Fatigue performance prediction method consider-ing joint characteristics

Members

Prof.

Y. MIKAMI

Welding and joining technologies are required to achieve the high-performance properties of materials, which are essential for manufacturing industrial products and structures. There is a demand for innovative welding and joining technologies that can be applied to similar and dissimilar materials.
The Department of Joining Metallurgical Evaluation researches to improve the properties and reliability of welding joints when welding similar or dissimilar materials using high-performance materials, with a focus on fusion welding and solid-state joining. Our department elucidates the governing mechanisms in the formation process of welds and research to develop new welding technologies that can control the properties of weld joints.

Evaluation and analysis of hot cracking susceptibility test

Observation of pitting initiation in heat-affected zone by FESEM
(a)α/γInterface and (b)α-ferrite, (c)Location of pitting initiation

Comparison of cross-sections of the dissimilar metal series micro-projection welded joints at different main weld times between experimental and numerically calculated results on the positive electrode side

Members

Prof.

R. IKEDA

Assoc. Prof.

K. KADOI