scholarly journals Behavior of bolted joints tightened in plastic region. Fundamental experiment and proposal of new torque control method.

1987 ◽  
Vol 53 (3) ◽  
pp. 416-421
Author(s):  
Kazuo MARUYAMA ◽  
Masato NAKAGAWA
Keyword(s):  
Control Method ◽  
Plastic Region ◽  
Torque Control ◽  
Bolted Joints ◽  
Fundamental Experiment

Improvement of Tightening Accuracy of Torque Control Method by Taking Account Geometric Errors in Threaded Fasteners

2016 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Keisuke Nakano
Keyword(s):  
Control Method ◽  
Primary Source ◽  
Torque Control ◽  
Bolted Joints ◽  
Large Scatter ◽  
Bearing Surface ◽  
Threaded Fasteners ◽  
Bolt Preload ◽  
Essential Problem ◽  
Easy Operation

Torque control method is commonly used when tightening bolted joints because of its easy operation. However, the method involves an essential problem of fairly large scatter in bolt preloads. It has been reported that even if the same torque is applied, bolt preloads show a considerable scatter, e.g., ranging from 25% to 35%. A scatter in coefficients of friction on nut bearing surface and thread pressure flank is a primary source of bolt preload scatter. Meanwhile, the effect of Equivalent Friction Diameter at the bearing surfaces of nut and bolt head cannot be ignored. The scatter in Equivalent Friction Diameter is caused by imperfect geometry, i.e., the flatness deviation at the bearing surfaces. In this paper, the magnitudes of Equivalent Friction Diameter are quantitatively evaluated by FEA, using the experimental data of flatness deviation measured for a number of commercial nuts and bolts. It is shown that the bolt preload is likely to be scattered by as much as plus minus 10% of the target value, owing to the flatness deviation. Based on the comprehensive calculations by considering the imperfect geometry, a strategy to effectively suppress the bolt preload scatter is proposed.

Application of Plastic Region Tightening Bolt to Flange Joint Assembly: Behavior of Bolt Preload in Flange Joint Subjected to Internal Pressure

2007 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Axial Force ◽  
Control Method ◽  
Plastic Region ◽  
Torque Control ◽  
Flange Joint ◽  
Allowable Limit ◽  
Torque Wrench ◽  
Assembly Behavior ◽  
Joint Assembly

Elastic region tightening by means of the torque control method is a conventional method to tighten bolts. The bolt axial force is controlled by a torque wrench; however, it is not easy to achieve constant bolt axial force. When the torque control method is applied to the flange joint assembly, the scatter of the bolt axial force is significant with respect to the joint reliability, such that it may cause leakage of the internal fluid from the flange joint. Recently, plastic region tightening has received considerable attention, which provides good uniformity in the bolt axial force. In a previous study, plastic region tightening was applied to a flange joint assembly, and the superior uniformity of the bolt axial force was demonstrated. The present paper describes the behavior of the plastic region tightening bolt in a flange joint subjected to internal pressure. First, the flange joint is tightened to the plastic region using a downsized bolt. The internal pressure is then applied to the flange joint, and the behavior of the additional bolt axial force is investigated. Application of plastic region tightening to the flange joint assembly is found to be effective for obtaining leak-free joints and for downsizing of the nominal diameter of the bolt. The behavior of the bolt axial force in a flange joint subjected to internal pressure was clarified. The additional bolt axial force has a sufficient margin for the allowable limit.

Evaluations of the Tightening Process of Bolted Joint With Elastic Angle Control Method

2004 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Tomohiro Takaki
Keyword(s):  
Surface Roughness ◽  
Rotation Angle ◽  
Control Method ◽  
Plastic Region ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Bolt Stress ◽  
Loaded Surface ◽  
Contact Surfaces ◽  
Inclined Angle

Various clamping methods are used to tighten bolted joints and the selection is made according to its configuration, bolt size, etc. Angle control method is commonly used among them and it is usually applied when tightening bolts to the plastic region. However, elastic angle control method is sometimes used to tighten important structures, e.g., for the case where the clamping bolts are to be disassembled in a periodical inspection. In this paper, the tightening process of elastic angle control method is studied and the expression relating axial bolt force and nut rotation angle is proposed, in which the effects of surface roughness of contact surfaces and the inclined angle existing around nut loaded surface are incorporated. The validity of the proposed equation is demonstrated by experiment. It is shown that the elastic angle control method is preferably applied to the case of a bolted joint with large grip length being tightened with high bolt stress.

Application of Plastic Region Tightening Bolt to Flange Joint Assembly

2006 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Axial Force ◽  
Control Method ◽  
Plastic Region ◽  
Elastic Interaction ◽  
Torque Control ◽  
Elastic Region ◽  
Flange Joint ◽  
Tightening Force ◽  
Torque Wrench ◽  
Joint Assembly

Elastic region tightening based on torque control method is conventional method of tightening a bolt. Axial force of the bolt is controlled by a torque wrench, however, it is not easy to achieve uniform bolt tightening force. When torque method is applied to flange joint assembly, the scatter of the bolt tightening foeces are large. They might cause the leakage of the internal fluid from a flange joint. Recently, plastic region tightening is remarked for critical applications, which provides good uniformity in bolt preloads and high preloads compared with the elastic region tightening. In this research, the plastic region tightening is applied to flange joint assembly and its superiority in uniformity of the bolt tightening force is demonstrated. For the tightening tests, JPI-4inch flange, spiral wound gaskets and M16 bolts were used. Axial force and elongation of all bolts in the flange were measured. Bolts were tightened by modified HPIS flange tightening procedure which incorporates the angle control method into the clockwise tightening sequence. Experimental results show that variations of the axial force in the plastic region was smaller than those in the clastic region. The influence of the elastic interaction on the axial force in the plastic region is also small. It is concluded that the application of plastic region tightening to flange joint assembly is effective for the leak-free joint and that the nominal diameter of the bolt can be reduced.

scholarly journals Stability Control for Electric Vehicles with Four In-Wheel-Motors Based on Sideslip Angle

2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Kun Yang ◽  
Danxiu Dong ◽  
Chao Ma ◽  
Zhaoxian Tian ◽  
Yile Chang ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Control Method ◽  
Sliding Mode ◽  
Stability Control ◽  
Torque Control ◽  
Wheel Load ◽  
Sideslip Angle ◽  
Distribution Method ◽  
Load Rate ◽  
The Stability

Tire longitudinal forces of electrics vehicle with four in-wheel-motors can be adjusted independently. This provides advantages for its stability control. In this paper, an electric vehicle with four in-wheel-motors is taken as the research object. Considering key factors such as vehicle velocity and road adhesion coefficient, the criterion of vehicle stability is studied, based on phase plane of sideslip angle and sideslip-angle rate. To solve the problem that the sideslip angle of vehicles is difficult to measure, an algorithm for estimating the sideslip angle based on extended Kalman filter is designed. The control method for vehicle yaw moment based on sliding-mode control and the distribution method for wheel driving/braking torque are proposed. The distribution method takes the minimum sum of the square for wheel load rate as the optimization objective. Based on Matlab/Simulink and Carsim, a cosimulation model for the stability control of electric vehicles with four in-wheel-motors is built. The accuracy of the proposed stability criterion, the algorithm for estimating the sideslip angle and the wheel torque control method are verified. The relevant research can provide some reference for the development of the stability control for electric vehicles with four in-wheel-motors.

A PD Computed Torque Control Method with Online Self-gain Tuning for a 3UPS-PS Parallel Robot

Robotica ◽  
2021 ◽  
pp. 1-13
Author(s):  
Xiaogang Song ◽  
Yongjie Zhao ◽  
Chengwei Chen ◽  
Liang’an Zhang ◽  
Xinjian Lu
Keyword(s):  
Feedback Loop ◽  
Control Method ◽  
Virtual Work ◽  
Parallel Robot ◽  
Torque Control ◽  
Virtual Work Principle ◽  
Tuning Method ◽  
Computed Torque Control ◽  
Control Feedback ◽  
Computed Torque

SUMMARY In this paper, an online self-gain tuning method of a PD computed torque control (CTC) is used for a 3UPS-PS parallel robot. The CTC is applied to the 3UPS-PS parallel robot based on the robot dynamic model which is established via a virtual work principle. The control system of the robot comprises a nonlinear feed-forward loop and a PD control feedback loop. To implement real-time online self-gain tuning, an adjustment method based on the genetic algorithm (GA) is proposed. Compared with the traditional CTC, the simulation results indicate that the control algorithm proposed in this study can not only enhance the anti-interference ability of the system but also improve the trajectory tracking speed and the accuracy of the 3UPS-PS parallel robot.

Computed Torque Control Method for Two-Axis Planar Serial Robotic Arm

2021 ◽  
pp. 1-9
Author(s):  
G. Perumalsamy ◽  
Deepak Kumar ◽  
Joel Jose ◽  
S. Joseph Winston ◽  
S. Murugan
Keyword(s):  
Control Method ◽  
Torque Control ◽  
Robotic Arm ◽  
Computed Torque Control ◽  
Computed Torque
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