Firstly evaluating equation of ultimate deformation for reinforced concrete columns with side walls is proposed in the case that the side wall is subjected to compressive axial force. The feasibility of the proposed equation is examined using thirty nine columns with side walls and four beams with spandrel walls. Secondly evaluating method of member ranks, which represents the level of deformation capacity of the member, is proposed. Whereas evaluated member ranks using previous methods shows too conservative deformation capacity comparing to experimental data, the proposed method is found to be an effective method for practical design procedures.
Multi-walled carbon nanotube (MWNT) and vapor grown carbon fiber (VGCF) were blended into poly (vinylidene fluoride) (PVDF) to enhance the piezoelectricity of the neat polymer. The PVDF composite films were prepared by solution casting method, stretched uniaxially and poled in silicon oil. The nanofiller contents range from 0.05 to 0.3 wt.%. Open circuit output voltage and energy harvesting tests indicate that both the PVDF/MWNT and PVDF/VGCF composite films approached the maximum output at the nanofiller content of 0.05 wt.%. Compared to the neat PVDF films, the maximum increasing rates of open circuit voltage and harvested power density are 24% and 47% for the PVDF/MWNT films and 15% and 78% for the PVDF/VGCF films, respectively. X-ray diffraction analysis showed an increase in content of the β phase in the PVDF composites; thus, the piezoelectric properties, which are dependent on β phase content, were enhanced. Stretching of the films leads to the transformation of PVDF from α phase to β phase form. Moreover, the addition of nanofillers, such as MWNT and VGCF, improves this transformation since the nanofillers provide a phase transformation nucleation function.
When RC columns reach near-collapse and undergo axial shortening following shear failure, some of axial load sustained by the columns transfer to neighboring columns and axial load of the columns becomes lower than the initial one. This study was intended to examine the effect of the decreased axial load on the collapse behavior. Full-scale column specimens with shear failure mode were tested under decreased axial load or constant axial load until they collapse. The effect of varied rates of the axial load decrease on the column collapse drift is studied and the comparison of computed collapse drifts and observed ones are also discussed.
This paper presents a controller design to reduce consumed energy for gantry-type feed drive systems which consist of two linear actuators placed in parallel and one linear actuator placed perpendicular to the two parallel actuators. Synchronous controller design has been widely studied for two parallel actuators because positional (synchronous) error between them causes not only control performance deterioration but also significant mechanical damage to the feed drive system. Although the existing synchronous controller design aims to reduce the synchronous error, this paper first presents a new design that is effective to reduce consumed electric energy while maintaining the synchronous control performance. Contouring controller for multi-axis feed drives is also widely studied thus far, which aims to reduce contouring error in machining and coordinate measurement. This paper next presents a combined synchronous and contouring controller that aims to reduce consumed electric energy while maintaining the contouring control performance in gantry-type feed drive systems. Experimental results show the effectiveness of the proposed controller by which consumed electric energy is reduced by about 7%.
The moromi fermentation process plays an important role in determining sake quality of the brewed sake, especially of Ginjo sake.This paper investigates a method for estimating the Ginjo sake quality by analyzing data from the moromi process and by using the AHP technique.Eleven factors, such as the process patterns of alcohol and Baume, are chosen from the data to estimate the sake quality.Six test samples of Ginjo sake were supplied for this study by a sake brewing maker in Akita.The Ginjo sake samples are rated using a five point scale for each factor with reference to the Ginjo brewing knowledge of the corresponding expert.The AHP technique is applied based on the rated data from the estimation of sake quality for all the Ginjo samples.The Ginjo sake samples are thus ranked according to the estimates of sake quality.These samples are also ranked according to sensory evaluation regarding sake quality by the expert.The former ranking is very similar to the latter.This shows the usefulness of the method investigated in this study.This method also acts as a concrete representation of the experience and expertize of the sake brewing experts.
The authors have newly developed a Narrow-Gap One-side Horizontal CO2 Arc Welding Process (NOW-H Process) for on-site welding of column to column joints of steel structures of building.In this paper, mechanism of the formation of reverse-side bead is discussed experimentally to establish the basis of the NOW-H Process. Formation of reverse-side bead in the horizontal position welding is different from that of the flat position, as already mentioned in the Report 2. In the horizontal position welding, concavity of the reverse-side bead is apt to occur at the root of upper side plate, and also the shape of 1st pass is prone to become convexity, resulting in the lack of fusion in the medium of 1st and 2nd layer.Accordingly, in order to prevent these weld defects and obtain a steady reverse-side bead, adequate backing methods are needed.Effects of diameter of wire, root-opening, arc voltage and other factors on the formation of reverseside head are described.
This report shows the structural retrofitting of a two-story reinforced-concrete (RC) welfare-facility building in Niigata prefecture, which was built in 2002. During the Chuetsu earthquake in 2004, the first floor window under the bathroom was damaged. Our investigation revealed that the damage was caused by an error in the structural design and insufficient girder strengths. Thus, such RC girders were retrofitted using the beam string structures composing steel members. The stress was reduced by introducing a pushing force to satisfy the allowable stress. This method was simple, easy to install, and economical.
