Calculating the load efficiency of a lowbed trailer requires considering multiple factors, including the trailer's deadweight, maximum allowable gross mass, axle load distribution, and cargo loading method. Here are the specific calculation methods and steps:
1. Determine the trailer's deadweight
The trailer's deadweight refers to the weight of the trailer when it is unloaded, including the weight of all parts such as the body, suspension system, brake system, tires, etc. This data can usually be found in the vehicle's certificate or technical manual.
2. Find the maximum allowable gross mass
The maximum allowable gross mass refers to the maximum allowable weight of the trailer when fully loaded, including the trailer's deadweight and the weight of the cargo. According to GB1589 "Outline dimensions, axle loads and mass limits of automobiles, trailers and automobile trains", trailers with different axle numbers have different maximum allowable gross mass limits:
- One-axle semitrailer: Maximum allowable gross mass limit is 18 tons
- Two-axle semitrailer: Maximum allowable gross mass limit is 35 tons
- Three-axle semitrailer: Maximum allowable gross mass limit is 40 tons
- Four-axle semitrailer: Maximum allowable gross mass limit is 36 tons
- Five-axle semitrailer: Maximum allowable gross mass limit is 43 tons
- Six-axle semitrailer: Maximum allowable gross mass limit is 49 tons
3. Calculate available load
Available load refers to the maximum weight of cargo that can be loaded on a trailer, and the calculation formula is as follows:
\[ \text{Available load} = \text{Maximum allowable gross mass} - \text{Trailer deadweight} \]
4. Consider axle load distribution
Axle load refers to the load borne by each axle. In order to ensure the stability and safety of the vehicle, the axle load needs to be reasonably distributed to avoid overloading or unbalanced loading. The calculation formula of axle load is as follows:
\[ \text{Axle load of each axle} = \frac{\text{Available load}}{\text{Number of axles}} \]
5. Consider the cargo loading method
The cargo loading method will also affect the loading efficiency. Reasonable loading method can improve space utilization, reduce the shaking and displacement of cargo, and ensure the safety of transportation. For example, cargo should be evenly distributed on the cargo platform of the trailer to avoid uneven loading.
6. Calculate loading efficiency
Loading efficiency refers to the ratio of the actual load of the trailer to the maximum allowable load. The calculation formula is as follows:
\[ \text{Loading efficiency} = \frac{\text{Actual load}}{\text{Available load}} \times 100\% \]
Example calculation
Suppose there is a three-axle low-bed trailer with a deadweight of 10 tons and a maximum allowable total mass of 40 tons.
① **Determine trailer deadweight**: 10 tons
② **Find the maximum allowable gross mass**: 40 tons
③ **Calculate available load**:
\[ \text{Available load} = 40 \text{tons} - 10 \text{tons} = 30 \text{tons} \]
④ **Consider axle load distribution**:
\[ \text{Axle load per axle} = \frac{30 \text{tons}}{3} = 10 \text{tons} \]
⑤ **Consider cargo loading method**: Assume that 25 tons of cargo are actually loaded and the cargo is evenly distributed on the cargo platform.
⑥ **Calculate load efficiency**:
\[ \text{Load efficiency} = \frac{25 \text{tons}}{30 \text{tons}} \times 100\% \approx 83.33\% \]
Through the above steps, the load efficiency of the low-bed trailer can be accurately calculated. Ensuring that the trailer can maximize its load-carrying efficiency while maintaining safety and stability can effectively reduce transportation costs and improve transportation efficiency.