Xiaomin Zhao, Fuminobu Ozaki, Takeo Hirashima, Kei Kimura, Yukio Murakami, Jun-ichi Suzuki and Naoya Yotsumoto
The main purpose of this study was to propose theoretical calculation models to evaluate the theoretical bending strengths of welded wide-flange section steel beams with local…
Abstract
Purpose
The main purpose of this study was to propose theoretical calculation models to evaluate the theoretical bending strengths of welded wide-flange section steel beams with local buckling at elevated temperatures.
Design/methodology/approach
Steady-state tests using various test parameters, including width-thickness ratios (Class 2–4) and specimen temperatures (ambient temperature, 400, 500, 600, 700, and 800°C), were performed on 18 steel beam specimens using roller supports to examine the maximum bending moment and bending strength after local buckling. A detailed calculation model (DCM) based on the equilibrium of the axial force in the cross-section and a simple calculation model (SCM) for a practical fire-resistant design were proposed. The validity of the calculation models was verified using the bending test results.
Findings
The strain concentration at the local buckling cross-section was mitigated in the elevated-temperature region, resulting in a small bending moment degradation after local buckling. The theoretical bending strengths after local buckling, evaluated from the calculation models, were in good agreement with the test results at elevated temperatures.
Originality/value
The effect of local buckling on the bending behaviour after the maximum bending strength in high-temperature regions was quantified. Two types of calculation models were proposed to evaluate the theoretical bending strength after local buckling.
Details
Keywords
Yukio Tamura, Fumiaki Kobayashi, Osamu Suzuki, Yasushi Uematsu and Yasuo Okuda
Human beings spend their daily lives within the range of the atmospheric boundary layer, where airflow is affected by friction from Earth's surface. The airflow in this area is…
Abstract
Human beings spend their daily lives within the range of the atmospheric boundary layer, where airflow is affected by friction from Earth's surface. The airflow in this area is generally called wind. Strong wind occasionally causes severe damage to infrastructures and people because of its aerodynamic effects, but even weak and moderate winds can have serious environmental impacts on human society such as those seen with air-pollution problems and thermal effects.
Xinyu Zhang and Liling Ge
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body and quality evaluation. This paper aims to discuss the…
Abstract
Purpose
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body and quality evaluation. This paper aims to discuss the aforementioned idea.
Design/methodology/approach
First, the differential body is set on a rotation platform before measuring. Then one laser sensor called as “primary sensor”, is installed on the intern of the differential body. The spherical surface and four holes on the differential body are sampled by the primary sensor when the rotation platform rotates one revolution. Another sensor called as “secondary sensor”, is installed above to sample the external cylinder surface and the planar surface on the top of the differential body, and the external cylinder surface and the planar surface are high in manufacturing precision, which are used as datum surfaces to compute the errors caused by the motion of the rotation platform. Finally, the sampled points from the primary sensor are compensated to improve the measurement accuracy.
Findings
A multi-laser sensors-based measurement instrument is proposed for the measurement of geometry errors of a differential body. Based on the characteristics of the measurement data, a gradient image-based method is proposed to distinguish different objects from laser measurement data. A case study is presented to validate the measurement principle and data processing approach.
Research limitations/implications
The study investigates the possibility of correction of sensor data by the measurement results of multiple sensors to improving measurement accuracy. The proposed technique enables the error analysis and compensation by the geometric correlation relationship of various features on the measurand.
Originality/value
The proposed error compensation principle by using multiple sensors proved to be useful for the design of new measurement device for special part inspection. The proposed approach to describe the measuring data by image also is proved to be useful to simplify the measurement data processing.