China
Africa
Explore chapters and articles related to this topic
Rigging and Material Handling Safety
Published in Frank R. Spellman, Kathern Welsh, Safe Work Practices for Wastewater Treatment Plants, 2018
Frank R. Spellman, Kathern Welsh
Another common problem encountered by safety and health engineers involving the resolution of forces occurs in material handling operations in moving a load (a cart, for example) up or down an inclined plane (a ramp or tilted surface, in our example). The safety implications in this type of work activity should be obvious. Objects are known to accelerate down inclined planes because of an unbalanced force (anytime we deal with unbalanced forces, safety issues are present and must be addressed). To understand this type of motion, it is important to analyze the forces acting upon an object on an inclined plane. Figure 16.6 depicts the two forces acting upon a load positioned on an inclined plane (assuming no friction). As shown in Figure 16.6, there are always at least two forces acting upon any load that is positioned on an inclined plane—the force of gravity (also known as weight) and the normal (perpendicular) force. The force of gravity acts in a downward direction; yet, the normal force acts in a direction perpendicular to the surface. Let’s take a look at a typical example of how to determine the force needed to pull a fully loaded cart up a ramp (an inclined plane).
Power Screws
Published in Keith L. Richards, Design Engineer's Sourcebook, 2017
The frictional force is dependent on the normal force. As a result, the effect of the thread angle is to increase the fictional force by the term (sec θ). To account for this, the coefficient of friction is taken as (μ sec θ) instead of (μ).
Multi-parameter responses and strong motions induced by fracturing of geomaterials and slippage of discontinuities and faulting model tests
Published in Ömer Aydan, Rock Dynamics, 2017
The maximum frictional resistance is given by Fy=μsN where µs is static friction angle and N is normal force. Normal force N is equal to block weight (W) shown in Figure 4.18 and it is equal to mg (m is mass and g is gravitational acceleration).
Fiber-on-fiber friction measurement using hanging fiber method
Published in The Journal of The Textile Institute, 2018
Azam Alirezazadeh, Mohammad Zarrebini, Mohammad Ghane, Parham Soltani
Ajayi (1992) characterized the frictional behavior of fibers in terms of parameters such as frictional resistance, force amplitude and static and dynamic frictional forces. The influence of variables such as normal force, sliding velocity, sliding frequency, and the nature of surfaces on coefficient of friction was investigated. It was observed that the coefficient of friction decreases with an increase in normal force. It was also concluded that the frictional force and normal force are not linearly related and Equation (4) was proposed:
Dynamic characteristics evaluation of balance valve for seawater hydraulic variable ballast system considering the depth variation
Published in Ships and Offshore Structures, 2022
Zhenyao Wang, Yinshui Liu, Qian Cheng, Hao Pang, Yunxiang Ma, Shendan Zhao, Wei Wang, Defa Wu
The product of the contact stress and the contact area is the normal force between the O-ring and the valve body, which can be obtained by Ansys/Workbench. Then the product of the normal force and the friction coefficient is the friction force. Taking the friction coefficient as 0.1, which was obtained through experiments and simulations, the friction force can be obtained, as shown in Figure 16. The friction force mentioned here is the static friction force. And the O-ring is in a water-lubricated state.