The appearance of FRP radomes is probably a bit of a problem for everyone. Most of them are hemispherical and don’t look very technical. So why do you think they cost so much? First of all, the price of FRP material is more expensive than other materials, but the weather resistance and wave permeability of FRP determine that it is the preferred material for radome. Secondly, its design process is not simple, the following by Yari Xiaobian to take you to understand its structure design.
One, laminated structure design
The design of laminated structure is particularly important in the design of FRP radome structure, which is not only related to the physical strength of the radome, but also related to the transmittance of the radome.
1. For radomes with diameter less than 300mm, the laminated structure shall be a layer of 300 grams of alkali-free glass fiber +450 grams of alkali-free glass fiber, and the thickness of the finished product shall be between 1.7mm-2.2mm.
2. For a radome with a diameter greater than 300mm and less than 600mm, the laminated structure shall be one layer of 300g alkali-free glass fiber + two layers of 450g alkali-free glass fiber, and the thickness of the finished product shall be between 2.6-3.1mm.
3. The diameter of the radome is greater than 600mm and less than 800mm. For the radome with this diameter, the laminated structure should be 300 grams of alkaline-free glass fiber two layers +450 grams of alkaline-free glass fiber two layers, and the thickness of the finished product should be between 2.9-3.4mm. It should be noted that the structure design of FRP radome of this size is different from that of conventional ones. In order to increase the strength of the installation position, the installation flange should be reinforced, that is, a layer of 450 grams of alkali-free glass fiber should be added to the installation flange, so that the thickness of the installation flange is about 3.8-4.2mm. Of course, some customers want to make the thickness of the mounting flange about 5mm, so only need to add a layer of 450 grams of non-alkali glass fiber, so that the thickness of the flange will be between 4.7-5.1mm;
4. It is necessary to pay attention to the structural design of FRP radome with a diameter larger than 800mm. It can no longer be completed by relying on the support force of FRP itself, because once the thickness of FRP radome is too thick, the wave transmission rate will drop exponentially and the transportation cost will rise linearly. In this case, stainless steel or aluminum frame should be made inside the radome, and the FRP cover body should be made into a piecewise assembly structure.
Two, installation structure design
The design of mounting structure is also an important aspect in the design of FRP radome structure. For the structure design of FRP radome with diameter less than 600mm, the installation structure can directly adopt the design scheme of casing side drilling; For radomes with a diameter between 600mm and 800mm, flange connection is recommended, because the bearing capacity of the radome should be taken into account on the one hand, and the deformation on the other hand. For radomes with a diameter of more than 800mm, the occlusal between fragments and the water resistance after occlusal should be considered in the fragment design.
The above is the specific design requirements of FRP radome structure. Anyway, the process requirements are quite complex, so although it is a spherical shell, but the technical requirements are very high, so its price is not cheap.