Enhance NVH performance

The noise generated by cars is one of the important reasons that currently affect the urban environment. The car needs to prepare a good operating environment for the driver. NVH is a key criterion affecting the overall level of the car. The NVH situation of automobiles is one of the characteristics of the whole vehicle that the major automobile manufacturers and affiliates of the global automotive industry pay attention to. Among them, reducing the front blocking radiation power and the vibration radiation noise to the seat cabin is an important indicator of NVH. The scientific design of the ribs can improve this indicator. For example, after the ribs are added to the middle section of the front panel of the car and the wheel hoods on both sides, the high value of the radiated sound pressure level zui of the driver's ear is reduced from 130 dB/N to 71 dB/N, which greatly improves the radiation power of the front partition. Level and the radiated sound pressure level of the driver's ear noise.

Enhanced strength performance

Strength refers to the ability of a metal material to never deform and fission under force. The changes in metal pressure under stress mainly include three continuous steps: elastic change, elastoplastic change, and fracture. When the pressure reaches the deformation limit, the metal will produce a significant plastic change; when the pressure reaches the strength limit, the metal will break. Adding ribs in the appropriate area increases the strength of the area and reduces the risk of failure.

Enhanced stiffness performance

Stiffness refers to the effectiveness of a metal or tissue against elastic deformation when compressed. The curved member has a rebound condition, and the rigidity of the deformed region must be increased when the curved member is studied. For example, adding reinforcing ribs at the turning position can increase the strength and rigidity of the stamping parts and reduce the rebound. After the rib is added to the bracket, the rigidity of the part is enhanced and the amount of rebound is reduced.

Design key and precautions

On the automotive sheet metal parts, it is not necessary to install the reinforcing ribs everywhere, nor does it mean that there are reinforcing ribs that will work better. Cars have a variety of functional requirements, and in some cases, stiffeners can improve certain functions and may affect other functions. Assuming that incorrect ribs are installed in the incorrect area, it may cause damage to the car as a whole. Therefore, in the design, it is necessary to pay attention to the application of the reinforcing ribs to the whole automobile, so as to avoid the counter effect. The following describes the key points and precautions for the design of some ribs.

Direction of attention

When reinforcing ribs are required to reinforce the part, the orientation of the ribs must be consistent with the direction of the force; if partial weakening is required, care must be taken that the direction is perpendicular to the direction of the force, for example, crushing ribs. According to the orientation of the force, the same rib has different effects.

Understand the weak parts of the ribs

The ribbed Zui's simple configuration is that a long strip of cylindrical body is attached to the surface of the part in a straight line shape, in addition to a triangular rib. In fact, the ribs of various shapes are located in a partially fragile position during the stamping process. Therefore, if it is not a special requirement, the reinforcing ribs do not have to be connected to each other or are too complicated. Otherwise, there are different manufacturing processes under various structural conditions, and the complicated reinforcing ribs are more prone to fracture than the simple reinforcing ribs, causing the performance of the automobile. opposite effect. It has been proved that the stamping CAE analysis of the steel plate's thinning rate to 20% and above does not need to be re-reinforced.

Master structure and vehicle performance

In the support design such as the sill beam, in order to enhance the support efficiency, there are the following methods: reduce the high bending moment of zui, or apply the scientific cross-sectional shape to enhance the flexural section modulus. Therefore, reinforcing the ribs in the beam cavity area does not drastically change the critical reinforcement section, otherwise the performance will be degraded; the ribs should not be made lower, which will cause the moment of inertia of the section to be disturbed. Therefore, the cavity formed by the inner panel of the sill and the side wall must be consistent, and the rib of the inner panel should face the inside instead of facing outward.