Yasuaki Hashikura, Koji Takahashi, Yuji Miyazaki, Keiji Houjou and Kotoji Ando
The purpose of this paper is to study the effects of overload on the threshold stress intensity factor range (ΔKth) in SUS316.
Abstract
Purpose
The purpose of this paper is to study the effects of overload on the threshold stress intensity factor range (ΔKth) in SUS316.
Design/methodology/approach
The fatigue tests are carried out to determine the resultant threshold stress intensity factor range (ΔKth). The mechanism of the improvement of ΔKth by the tensile overloading is analyzed using the Dugdale model.
Findings
It is clarified that the value of ΔKth increases as increasing the overloading.
Research limitations/implications
The apparent value of ΔKth of stainless steel can be improved by a tensile overload, the fatigue strength of structural members that have a surface crack can be increased by a tensile overload.
Originality/value
As a result, the reliability and safety of structures, such as energy plants, can also be improved.
Details
Keywords
Yuji Shindo, Akihisa Kameari and Tetsuji Matsuo
This paper aims to discuss the relationship between the continued fraction form of the analytical solution in the frequency domain, the orthogonal function expansion and their…
Abstract
Purpose
This paper aims to discuss the relationship between the continued fraction form of the analytical solution in the frequency domain, the orthogonal function expansion and their circuit realization to derive an efficient representation of the eddy-current field in the conducting sheet and wire/cylinder. Effective frequency ranges of representations are analytically derived.
Design/methodology/approach
The Cauer circuit representation is derived from the continued fraction form of analytical solution and from the orthogonal polynomial expansion. Simple circuit calculations give the upper frequency bounds where the truncated circuit and orthogonal expansion are applicable.
Findings
The Cauer circuit representation and the orthogonal polynomial expansions for the magnetic sheet in the E-mode and for the wire in the axial H-mode are derived. The upper frequency bound for the Cauer circuit is roughly proportional to N4 with N inductive elements, whereas the frequency bound for the finite element eddy-current analysis with uniform N elements is roughly proportional to N2.
Practical implications
The Cauer circuit representation is expected to provide an efficient homogenization method because it requires only several elements to describe the eddy-current field over a wide frequency range.
Originality/value
The applicable frequency ranges are analytically derived depending on the conductor geometry and on the truncation types.
Details
Keywords
The Lockheed scandal was exposed during the 4 February 1976 hearings of the Sub-Committee on Multinational Corporations of the United States Senate Committee on Foreign Relations…
Abstract
The Lockheed scandal was exposed during the 4 February 1976 hearings of the Sub-Committee on Multinational Corporations of the United States Senate Committee on Foreign Relations. These hearings revealed that Lockheed Aircraft Corporation paid illegal payments in several countries including Japan to promote the sale of its planes to prevent bankruptcy. The Securities Exchange Commission obtained documents showing that Lockheed paid more than US$10 million to Yoshio Kodama, a “fixer” and Lockheed's secret representative, and the Marubeni Corporation, which was Lockheed's agent in Japan since 1959. During the same hearings on 6 February, A. Carl Kotchian, vice president of Lockheed, informed the committee that a senior Japanese government official received US$2 million from Marubeni and that his company relied on Kenji Osano, a close associate of former Prime Minister Kakuei Tanaka, as an intermediary in its efforts to sell 21 Lockheed's L-1001 Tristar airbuses to All Nippon Airways (ANA) (Macdougall, 1988, pp. 193–195).
Fei Wang, Chengdong Wu, Xinthe Xu and Yunzhou Zhang
The purpose of this paper is to present a coordinated control strategy for stable walking of biped robot with heterogeneous legs (BRHL), which consists of artificial leg (AL) and…
Abstract
Purpose
The purpose of this paper is to present a coordinated control strategy for stable walking of biped robot with heterogeneous legs (BRHL), which consists of artificial leg (AL) and intelligent bionic leg (IBL).
Design/methodology/approach
The original concentrated control in common biped robot system is replaced by a master‐slave dual‐leg coordinated control. P‐type open/closed‐loop iterative learning control is used to realize the time‐varying gait tracking for IBL to AL.
Findings
The new control architecture can simplify gait planning scheme of BRHL system with complicated closed‐chain mechanism and mixed driving mode.
Research limitations/implications
Designing and constructing a suitable magneto‐rheological damper can greatly improve the control performance of IBL.
Practical implications
Master‐slave coordination strategy is suitable for BRHL stable walking control.
Originality/value
The concepts and methods of dual‐leg coordination have not been explicitly proposed in single biped robot control research before. Master‐slave coordinated control strategy is suitable for complicated BRHL.