What are the discussion on the damping performance of rubber shock absorber
Since rubber shock absorber plays a strong role in various mechanical equipment, its shock absorption performance will be studied for many times, and the following performance characteristics can be obtained from the results of various studies:
1. The rubber shape can be freely selected, the hardness can be adjusted by formula design, and can meet the requirements of stiffness and strength in different directions;
2. Rubber is non retrenchment data (Poisson's ratio is 0.5);
3. Rubber has high elasticity and viscoelasticity;
4. Compared with steel, rubber has a large elastic deformation and a small elastic modulus;
5. The impact stiffness of rubber is greater than the dynamic stiffness, and the dynamic stiffness is greater than the static stiffness, which is conducive to reducing the impact deformation and dynamic deformation;
6. The stress-strain curve is an elliptical hysteresis line, and its area is equal to the vibration energy (damping) converted into heat in each vibration cycle, which can be adjusted through formula design.

Why should waterproof casing be used in plastic pipes
The waterproof casing is a kind of pipe that we often use. It can be seen everywhere in our life, but can you understand it? This is the most professional introduction today. One of the functions of waterproof casing is to protect the pipeline from damage. The pipeline crosses the railway, crosses the road and receives other centers. In order to prevent the pipeline from being crushed by the load, a maintenance sleeve is installed outside the pipeline
For example, large-diameter concrete pipes, large-diameter steel pipes, etc., to avoid direct external force (load) on the outer wall of the pipeline, which may cause pipeline fracture, and take measures; The plastic pipes passing through the floor also need maintenance. For example, the above U-PVC drainage plastic pipes and sleeves are maintenance measures to prevent the pipe roots from being damaged by external forces. The most important thing for plastic pipes is the damage of tree roots, because they are difficult to maintain
Similarly, for plastic water supply pipes, the installation of sleeves on the floor is not only used for construction or maintenance, but also for maintaining the root from being damaged. As we all know, the shell of plastic water supply pipes does not need to pass through the floor, but there is a clear request for the height of the floor (See the rules) The pipeline passes through the foundation wall, the concrete shear wall, and the casing maintenance pipe is installed -- when the building is disposed, the difference between the pipeline and the casing, the difference between the pipeline and the building reduces the pressure pipeline of the building
When the pipeline passes through three joints (expansion joint, settlement joint and joint), in order to ensure that the pipeline is not broken or twisted on both sides of the building, waterproof casing is also required. This kind of casing usually has a special request. It can be customized according to the design request