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Prototyping of automated systems
Published in Fuewen Frank Liou, Rapid Prototyping and Engineering Applications, 2019
Using an inclined plane requires a smaller force exerted through a greater distance to do a certain amount of work. Letting F represent the force required to raise a given weight on the inclined plane with inclined slope length l and height h, and W the weight to be raised, the following proportion can be obtained:
Calibration of discrete element microparameters of coal based on the response surface method
Published in Particulate Science and Technology, 2021
Haozhou Ma, Xuewen Wang, Bo Li, Zisheng Wang, Chao Liang, Qingbao Bao
The calibration process for the intrinsic and contact parameters is relatively standardized. The intrinsic material parameters such as density and Poisson's ratio are calibrated experimentally according to the relevant standards. The contact parameters are calibrated by experimental measurements or by test–simulation joint calibration. The coefficient of restitution is generally calibrated by a free-fall test or single (double) pendulum test. The coefficient of static friction is generally calibrated by the inclined plate test, but it can also be calibrated by the horizontal traction, rotation, or shear test. The coefficient of rolling friction can be calibrated by the inclined plate or inclined plane test. No complete calibration process is available as yet for BPM parameters. UCTs (UCT and BST) are often used for the mechanical determination of samples, and discrete element models are established to match parameters close to the macroscopic characteristics. However, for different types of bulk materials, BPM parameters have different effects on macroscopic characteristics, and different parameter sets can achieve similar results. Therefore, it is necessary to calibrate parameters based on specific materials and analyze the influence of each parameter on macroscopic characteristics.
An innovative method for calculating diagonal lashing force of cargo on railway wagons in a curve alignment
Published in Vehicle System Dynamics, 2021
Duo Zhang, Yinying Tang, David B. Clarke, Qiyuan Peng, Chunjiao Dong
The wagon model is made up of the car body and three-piece freight bogies. The car body is represented by a rigid body. The primary suspension, denoted by a bushing with linear translational stiffness and damping, is the connection between the axlebox and sideframe. The sideframe is linked with the bolster by the secondary suspension. In order to decrease the vibration, two wedges are equipped between the bolster and sideframe to offer normal force and planar friction on the inclined plane and vertical plane of each wedge. The car body is connected with the bolster by the centerplate, consisting of a normal contact force, a planar friction force and an additional torque component around the normal direction to plane [39]. The side bearer is represented by a spring with gap to limit roll motion of the car body relative to the bolster.
A simple repair method of fatigue cracks using stop-holes reinforced with wedge members: applicability to reinitiated cracks and effects of an anti-fatigue smart paste
Published in Welding International, 2020
Figure 24 shows the changes for AW3 in Δl on the right of Equation (5) as the load cycles progress with time as the horizontal axis, for increments of 20 cycles immediately after loading and from N = 1200 cycles. Focusing on the data immediately after loading (the brown line), when the tensile load P reaches 75% of the peak of the first cycle, the wedge member responds to the deformation of the circular hole rotating the pulley and the wire is wound into the displacement metre accordingly. Immediately after loading, the wedge member cannot completely track the rapid deformation of the hole and the winding of the wire (and the extension of the wedge member) continues even when the loading cycle approaches the completely unloaded state and as the number of cycles increases further, the wedge member extends stepwise and the wedge effect increases and then gradually takes on an approximately steady appearance. It is also clear that Δl becomes an almost constant value (the green line) from N = 1200 cycles and a wedge stability is created by the frictional force between the inclined plane surfaces.