Structural Design of Electric Scooter Body: Engineering Practice from Material Selection to Lightweight Design

Keywords: electric scooter, body structure, carbon fiber, aluminum alloy, finite element analysis

abstract

The body structure determines the strength, weight, and cost of the scooter. This article analyzes the technical path and engineering cases from material selection, connection process to simulation optimization.

3.1 Comparison of Main Framework Materials

6061-T6 aluminum alloy:

The yield strength is 275MPa, the density is 2.7g/cm 3, and the cost is $5/kg, suitable for mid to low end vehicle models (such as the Maverick MQiL with a frame weight of 3.2kg).

T700 carbon fiber:

Tensile strength 4900MPa, density 1.8g/cm 3, cost $30/kg, weight reduction of 40% (such as Segway Ninebot MAX frame weight 1.8kg).

Magnesium alloy AZ91D:

Higher specific strength than aluminum alloy, but poor corrosion resistance (requiring surface treatment), cost $8/kg, and less application.

3.2 Optimization of Connection Process

FSW (Friction Stir Welding):

The welding strength reaches 90% of the base material (such as the connection between the aluminum alloy frame riser and the pedal), with no porosity/crack defects, but the equipment cost is high ($500000 per unit).

3D printed titanium alloy:

Using EOS M400-4 printer, with a layer thickness of 30 μ m and a density of 4.4g/cm 3, it can manufacture complex hollow structures (such as reducing weight by 20% for folding joints).

3.3 Folding mechanism design

Magnetic folding:

By using a neodymium iron boron magnet (N52) to provide 100N suction force, coupled with a locking switch, the folding time is less than 2s (such as the 9th F series).

Gear rack folding:

The carrying capacity is greater than 150kg, but the folding time takes 5 seconds (such as Inokim Quick 4).

3.4 Finite Element Analysis (FEA)

Static strength analysis:

Applying a load of 150kg in ANSYS Workbench, the maximum stress on the frame is less than 200MPa (safety factor 1.375).

Fatigue life prediction:

Simulate 100000 vibration cycles (frequency 10Hz) using nCode DesignLife, with fatigue life of key parts exceeding 5 years.

3.5 Ergonomic Optimization

Pedal width:

According to the ISO 11194 standard, a width of ≥ 150mm (such as the Yadi E8S pedal width of 160mm) can reduce foot fatigue.

Handle height:

The adjustable range is 800-1100mm (such as the Xiaomi Pro 2 using a telescopic riser), suitable for users with a height of 1.5-1.9m.

conclusion

Carbon fiber and aluminum alloy are mainstream materials, and the folding mechanism needs to balance speed and strength. Through FEA simulation and ergonomic optimization, vehicle performance and user experience can be improved.