Impact Variables of Dump Truck Cycle Time for Heavy Excavation Construction Projects

Song, Siyuan,Marks, Eric,Pradhananga, Nipesh Korea Institute of Construction Engineering and Ma 2017 Journal of construction engineering and project ma Vol.7 No.2

The cycle time of construction equipment for earthwork operations has a significant impact on project productivity. Elements that directly impact a haul vehicle's cycle time must be identified in order to accurately quantify the haul cycle time and implement strategies to decrease it. The objective of this research is to scientifically identify and quantify variables that have a significant impact on the cycle time of a dump truck used for earthwork. Real-time location data collected by GPS devices deployed in an active earthwork moving construction site was analyzed using statistical regression. External data including environmental components and haul road conditions were also collected periodically throughout the study duration. Several statistical analyses including a variance analysis and regression analysis were completed on the dump truck location data. Collected data was categorized by stage of the dump truck cycle. Results indicate that a dump truck's enter idle time, exit idle time, moving speed and driver visibility can significantly impact the dump truck cycle time. The contribution of this research is the identification and analysis of statistically significant correlations of variables within the cycle time.

Repair of bone defects using dynamic fabricated tissue-engineered bone based on a bio-derived porous bone scaffold

Kedong Song,Liying Li,Lili Ji,Siyuan Li,Chunfeng Mu,Yiwei Wang,Tianqing Liu 한국통합생물학회 2016 Animal cells and systems Vol.20 No.5

Fabrication and transplantation of tissue-engineered bones in a rotating wall vessel bioreactor (RWVB) was studied in the present study aiming to repair segmental bone defects. Osteoblasts were transfected with green fluorescent protein prior to seeding on bio-derived porous bone scaffolds at a density of 1 × 106 cells/mL and cultured in an RWVB for one week. For comparison, constructs were also cultured in a static condition. Morphology and structure of fabricated bones were examined using an inverted microscope, scanning electron microscope and histology analysis via hematoxylin–eosin and toluidine blue staining. Moreover, an animal model for repairing segmental bone defects of a Zelanian rabbit was used to assess the efficacy and biosafety of fabricated bones. In conclusion, tissue-engineered bones grew favorably in RWVB. In animal study, a preliminary repair of bone defects was noticed only in the experimental group after 4 weeks of implantation. Using RWVB, the fabricated tissue-engineered bone constructs were approved with better bio-capability in repairing the segmental bone defect.

Computational investigation of three-faced blade errors on contact behaviors for face-hobbed hypoid gears

Chaosheng Song,Chengcheng Liang,Caichao Zhu,Kunming Liu,Siyuan Liu,Qianhong Huang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

An accurate mathematical model of face-hobbed hypoid gear tooth surface based on the three-faced blade is established. The correctness of the mathematical model was verified by comparing the contact pattern results from KIMOS software and finite element tooth contact analysis. Then, the effects of tool errors on mesh characteristics of face-hobbed hypoid gear were investigated by loaded tooth contact analysis. Results show that the influences of pressure angle error and regrind angle error on contact pattern are obvious. The location of contact pattern moves from the root on the heel side to the top on the toe side of the tooth surface when the error value increases. The peak-to-peak value of transmission error gradually increases with those two types of errors. The influences of spheric radius error, rake angle error and cutting side relief angle error on contact behaviors are similar and not obvious for facehobbed hypoid gears.

Influences of machine-tool setting errors on mesh behavior for small-module spiral bevel gear

Chaosheng Song,Maohao Xia,Siyuan Liu,Chengcheng Liang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

Due to the complex manufacturing process and numerous machine-tool settings, errors easily arise between the actual parameters and theoretical parameters of spiral bevel gear, which contributes to the deviation of geometrical morphology of gear flank. This type of gear pair is very sensitive to tooth flank deviations, and the deviations can affect the mesh behavior of the gear pair and then the performance of the entire device. To investigate the influence of different machine-tool setting errors on the mesh behavior of small-module spiral bevel gear, a mathematical model of this type of gear pair has been established based on the principle of duplex spread blade method, and the finite element analysis model has been developed under the rated condition. The horizontals and radial distances of pinion and wheel as well as the velocity ratio were selected to be investigated. The three machine-tool setting all makes the contact pattern move within the tooth flank. The minimum value of transmission error (TE) appears at the initial horizontal and radial distance. Negative values of the horizontal and radial distance and positive value of velocity ratio both can increase the root bending stress. The errors of machine-tool setting will increase the tooth contact stress. The main influential errors on mesh behavior of small-module spiral bevel gear are in proper order, horizontal, radial distance and velocity ratio. It is convenient and efficient to correct the tooth flanks in this order only by contrasting the contact pattern with the design after the rolling test.

Mechanism of Wenshen Xuanbi Decoction in the treatment of osteoarthritis based on network pharmacology and experimental verification

You Hankun,Song Siyuan,Liu Deren,Ren Tongsen,Yin Song Jiang,Wu Peng,Mao Jun 대한약리학회 2024 The Korean Journal of Physiology & Pharmacology Vol.28 No.1

To investigate the mechanism of Wenshen Xuanbi Decoction (WSXB) in treating osteoarthritis (OA) via network pharmacology, bioinformatics analysis, and experimental verification. The active components and prediction targets of WSXB were obtained from the TCMSP database and Swiss Target Prediction website, respectively. OA-related genes were retrieved from GeneCards and OMIM databases. Protein-protein interaction and functional enrichment analyses were performed, resulting in the construction of the Herb-Component-Target network. In addition, differential genes of OA were obtained from the GEO database to verify the potential mechanism of WSXB in OA treatment. Subsequently, potential active components were subjected to molecular verification with the hub targets. Finally, we selected the most crucial hub targets and pathways for experimental verification in vitro. The active components in the study included quercetin, linolenic acid, methyl linoleate, isobergapten, and beta-sitosterol. AKT1, tumor necrosis factor (TNF), interleukin (IL)- 6, GAPDH, and CTNNB1 were identified as the most crucial hub targets. Molecular docking revealed that the active components and hub targets exhibited strong binding energy. Experimental verification demonstrated that the mRNA and protein expression levels of IL-6, IL-17, and TNF in the WSXB group were lower than those in the KOA group (p < 0.05). WSXB exhibits a chondroprotective effect on OA and delays disease progression. The mechanism is potentially related to the suppression of IL-17 and TNF signaling pathways and the down-regulation of IL-6.

Study on the effect of tooth blank parameters on mesh behavior of aviation bevel gear considering thin web and narrow rim structure

Shuaitao Zhao,Chaosheng Song,Siyuan Liu,Cheng Xu,Caichao Zhu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.7

This study establishes the mathematical model of aviation spiral bevel gear with tilt structure by considering the spatial relationship between cutter and gear blank involved machine-tool settings, and builds a finite element model for the spiral bevel gear with a thin web and narrow rim structure. It also investigates the influence law of different parameters of gear blank on the mesh characteristics. Results show that the decrement of the thickness of the rim does not influence the position of contact pattern. When the thickness of the rim is reduced, the tooth root stress shows an increasing trend and the peak-to-peak value of the transmission errors first decreases and then increases. A reduction of the web causes the position of contact pattern moving slightly from the center part to the heel. When the web thickness gets lower, the tooth root stress greatly declines, while the peak-to-peak value of the transmission errors keeps rising. When increasing the number of rows of the hole, the position of contact pattern gradually shifts from the middle to the heel, the changes of tooth root stress are not obvious, and the peak-to-peak value of the transmission errors initially decreases, but then increases afterwards.

Influences of rubber cushion and bearing position on the mesh characteristics of small-module spiral bevel gear

Maohao Xia,Chaosheng Song,Chengcheng Liang,Siyuan Liu,Zhengminqing Li,Peitang Wei 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

A mathematical model of spiral bevel gear with the application of duplex spread blade method was established. A novel finite element model considering the configuration of shafts and bearings was developed. The influences of shafts, bearing position, and rubber cushion on the mesh characteristics of spiral bevel gear under different loads were investigated. Results show that the peak-to-peak value of transmission error and the ratio of contact area and high stress area all increase with the increase in loads. With the existence of rubber cushion, the contact pattern moves to the heel and root sides of the wheel flank, and the peakto-peak value of transmission error and root edge contact area increase. With the front bearing moving from the original position to the positive position, the peak-to-peak value of transmission error increases. With the movement of rear bearing position from negative to positive, the contact pattern moves to the heel and root sides of the wheel flank. The peak-to-peak value of transmission error increases, and the root edge contact area expands.