Advantages and disadvantages of common lightweight materials

Why to promote lightweight materials:

1. Based on environmental considerations

Countries around the world are promoting policies to automobile manufacturers to reduce automobile fuel consumption. Some research data show that the car car weight reduction of 10%, fuel consumption increased by 6% -8% car overall weight per 100 kg, 100 kg fuel consumption reduction of 0.3-0.6 liters, CO2 emissions reduced by about 5g/km. It can be seen that the car's lightweight and the improvement of fuel economy, fuel economy, and even environmental protection and energy saving is closely related to the improvement of fuel economy, fuel economy, and even environmental protection and energy saving. Therefore, automobile lightweight has become the consensus of automobile enterprises.

2. Pressing the transformation of automobile manufacturing technology

If you can't ensure driving safety, no matter how light and fuel-efficient the car is, no one dares to drive. If the pursuit of absolute safety and collision resistance, can only drive dozens of tons of tanks, to withstand hundreds of liters of fuel consumption per hour. Therefore, lightweight is the trend of automobile manufacturing, and the current lightweight is mainly to reduce the self-weight of the car. Although the body, as the main carrier of the car, needs to ensure sufficient rigidity, strength and fatigue durability performance, so that the whole car has good safety, vibration noise and durability performance, but lightweighting puts forward higher requirements for these factors, undoubtedly, the transformation of automobile manufacturing technology has brought about a great stimulus.

Achieve the basic principles of automotive lightweight materials:

1. Ensuring sufficient rigidity

Rigidity refers to the ability of the material to deform to external forces, usually refers to the elastic properties of the body development especially before the material yields. Good stiffness is the basis for the NVH performance of the vehicle, vehicle dynamics and fatigue durability performance, and common evaluation indexes are the torsional stiffness of the body and so on. Stiffness is related to the modulus of elasticity of the material. Basically, the type of material is determined, and the modulus of elasticity is also determined. For example, the rigidity of a body will not increase even if high-strength steel is used. This is because all steels have the same modulus of elasticity.

2. Ensure adequate strength.

Strength refers to the ability of a part to maintain its function after yielding to an impact load, and is commonly used in the evaluation of body crash safety, impact resistance, and other properties. Strength is related to the yield strength and fracture strength of the material, in order to improve the safety performance of the car, the modern body design of high-strength steel is mostly used for this reason.

3. Maintain good fatigue durability performance.

Fatigue durability performance refers to the ability of components to maintain function after long-term exposure to alternating loads, the reliability and durability of the car is evaluated accordingly. Fatigue durability properties are related to the fatigue curve of the material, and of course, the fatigue properties of welded joints and other connections on the car are more important. Third, the method of realizing automobile lightweighting:

4. Optimize the car sound structure and improve the material utilization.

For example, in order to effectively disperse the collision energy when the car collides, change the lower part of the body from discontinuous to continuous; increase the ribs; strengthen the finite element method design of the roller balancing bar; adopt planetary frame body to make the thickness of the body bar thinner, etc.