Table of Contents
What is structural damping?
Structural damping includes: damping in a material of a structure, losses due to friction between contact areas, and dissipation in medium due to relative motion within the system [4]. The structural damping, thus, essentially covers the entire mechanical system (structure).
What is the value of damping for steel structure?
Speaking about damping ratio, we have for example for standard bolt structures 0.8 percent, and for welded structures 0.3 percent, while for reinforced concrete structures 5 percent.
What causes damping in a structure?
Viscous damping is caused by such energy losses as occur in liquid lubrication between moving parts or in a fluid forced through a small opening by a piston, as in automobile shock absorbers. The viscous-damping force is directly proportional to the relative velocity between the two ends of the damping device.
What are the effects of damping in structure?
Damping makes the vibration regular and smaller compared to undamped oscillation. As previously noted, earthquakes can be particularly disastrous to buildings through resonance. However, most structures have some amount of damping, which helps curbs resonance.
What is critical damping in structural dynamics?
Critical damping viewed as the minimum value of damping that prevents oscillation is a desirable solution to many vibration problems. Increased damping implies more energy dissipation, and more phase lag in the response of a system. Reduced damping means more oscillation, which is often undesirable.
What is damping in structural analysis?
Damping is the dissipation of vibratory energy in solid mediums and structures over time and distance. In construction, damping is essential for limiting vibrations and ensuring security and comfort in buildings and infrastructures.
How do you find the damping of a structure?
Damping is the conversion of mechanical energy of a vibrating structure into thermal energy. If we want to quantify the level of damping in a structure the absorbed energy per cycle must be determined. By plotting the force versus displacement for a given cycle of motion a hysteresis curve is generated (figure 1).
What factors affect damping?
The energy dissipation is caused by material damping which basically depends on three factors: amplitude of stress, number of cycles and geometry. In the case of non-homogeneous stress distribution the geometry of the structure influences the vibration damping.
What are main categories of structures regarding to damping?
2 Types of damping Types of damping are: viscous and hysteretic damping. Viscous damping depends on frequency. Hysteretic damping assumes non-linear relations between stress – deformations. Some materials, such as structural steel, are almost ideally elastic up to the elasticity limit.
What is damping ratio in structures?
The damping ratio is a dimensionless measure describing how oscillations in a system decay after a disturbance. The damping ratio is a system parameter, denoted by ζ (zeta), that can vary from undamped (ζ = 0), underdamped (ζ < 1) through critically damped (ζ = 1) to overdamped (ζ > 1).