Predicting the sinkage of a moving tracked mining vehicle using a new rheological formulation for soft deep-sea sediment

Semi-Empirical Time-Dependent Parameter of Shear Strength for Traction Force between Deep-Sea Sediment and Tracked Miner

“…The deep-sea simulant sediment is sampled into a standard cylinder shape of 60 mm × 30 mm (Figure 1) [10] by a ring knife, considering that its water content (w = 165.6%) is between the plastic limit and the liquid limit. The sheer creep test of simulant sediment (with constant compressive stress) is conducted on a self-developed pressure-shear creep test device (Figure 2) [20] by our research team. The simulant sediment sample is placed in a shear box and burdens the effect of vertical weights (compressive stress σ) and horizontal weights (shear stress τ), i.e., the pressure-shear loading.…”

“…As an example, Figures 3b and 4b show the curved 3D surface in τ-s-t space fitted by Equation (1) for the specific constant σ (σ = 5 kPa [20] and 10 kPa), where solid points are experimental data. By resorting to "Dynamic Fit Wizard" in the Sigma-plot software and inputting Equation (1) with user-defined function, the fitted Burgers rheological model parameters can be obtained (such as for the σ = 5 kPa, K1 = 7.36 MPa, K2 = 1.82 MPa, β1 = 7380 MPa•s, β2 = 22,900 MPa•s, coefficient of determination R-Square is 0.987).…”

“…Table 2 lists all of the fitted shear creep parameters under different σ as well as R-Square and illustrates that the fitted shear creep parameters are the functions of σ and increase with σ. Therefore, the shear rheological Equation (1) can express the relationships between shear stress τ, shear displacement s, compressive stress σ, and time t, i.e., τ = τ(s, σ, t) and can be rewritten as Equation (2), i.e., direct shear rheological constitutive model, where the expressions of K1(σ), K2(σ), β1(σ), and β2(σ) are obtained by fitting data in Table 2 [20] and described by Equation (3).…”

“…Since shear displacement s = vt and shear velocity v is constant, c is only the function of time t, i.e., c = c(t). Hence, the parameters K1(σ), K2(σ), β1(σ)and β2(σ) become constant and the value of the parameters are as follows [20].…”

“…Li et al [19] obtains a relationship between the grouser height and the water jet based on elasticplastic traction force model aiming at the cause of sticky soil shaped on the track. Experimentally, Xu et al [20] discussed the relationship between the slippage and traction force and determined the optimal grouser height by analyzing the motion of simplified track shoes and the track shoe experiment of different grouser heights. Shin et al [21] discussed the loss mechanism of the lateral thrusting force by a traction force experiment with different shape ratios.…”