Search Results (2)

Components of transport trucks are subjected to dynamic cyclic loads. The magnitude of these loads depends on road conditions and cargo mass. Cyclic loads can cause fatigue failure at stress levels significantly below the yield strength of the material. When calculating fatigue, it is necessary to determine the actual loads acting on the structure under working conditions. In this study, stanchion displacements of overloaded timber trucks were measured under both static and dynamic loads. For the specified mass of timber, a history of dynamic loads acting on the stanchion was obtained. Then, based on the finite element analysis, stress concentration points were determined within the base material and welded joints of the stanchion. The history of maximum stresses at concentration points was determined. Stress ranges and mean stresses for the load history were calculated using the rainflow fatigue cycle counting method. Repeats to failure were determined on the basis of the Palmgren–Miner cumulative damage rule and the modified Goodman correction for the points with the highest stress level. Experimental investigation of the actual load history of the stanchion of significantly overloaded timber truck allowed to determine the mileage to potential failure. Full article

In Ireland, timber and biomass haulage faces the challenge of transporting enough material within strict legal dimensions and gross vehicle weights restrictions for trucks and trailers. The objective of this study was to develop a method to control payload weight by knowing the moisture content of the wood. Weights, volumes, and moisture content were gathered from 100 truckloads of Sitka spruce pulpwood. Truck volume and weight utilization patterns were analyzed based on stacked volume, truck volume, and weights recorded from the weighbridge. Solid/bulk volume conversion factors for the truckloads were estimated indicating the truck’s solid volume capacity to be filled. Trucks were grouped into five conditions based on their configuration—volume capacity and legal maximum payload. A loaded volume fraction was estimated to assess the optimal volume capacity and stanchion height at which the trucks should be loaded. Results showed that 100% of the trucks presented volume underutilization, with a maximum of 27.5 m³ (only 39.85% volume capacity). In contrast, 67% of trucks were overweight while the remaining 33% were under the legal maximum weight. The average solid/bulk volume conversion factor was 0.66 ± 0.013 at 95% confidence level. Depending on the conditions, trucks can be filled to 100% of their volume capacity with wood at an MC from 29% to 55%. The minimum truck volume capacity utilization was 45%. This methodology can be used by truck hauliers, enabling them to determine in-forest the optimum volume and weight of wood to be transported by knowing the moisture content (MC), the wood specie, and using the height of the stanchions of the trailer as reference when loading the truck. Full article