Pulling Resistance Modeling

In contrast to the flow—or no-flow—situation, there appears to be a consensus on what mechanisms contribute to the pulling resistance of a die although some models choose to neglect certain contributions, the following model includes all contributions discussed in the literature. 

Engineering models of tractive effort calculation derive from a basic model, generally called the Davis formula (after its initial formulator, W. J. Davis). The Davis formula calculates the resistance (Rt, in pounds per ton of weight being pulled) as ... 

The physical properties of barrier dressings were evaluated using the Seiko Model DMS 210 Dynamic Mechanical Analyzer Instrument (see Fig. 2.45). Referring to Fig. 2.46, dynamic mechanical analysis consists of oscillating (1 Hz) tensile force of a material in an environmentally (37°C) controlled chamber (see Fig. 2.47) to measure loss modulus (E") and stored modulus (E ). Many materials including polymers and tissue are viscoelastic, meaning that they deform (stretch or pull) with applied force and return to their original shape with time. The effect is a function of the viscous property (E") within the material that resists deformation and the elastic property (E )... 

Theoretical model of mode I delamination of z-pinned DCB has been developed to study the bridging mechanism of z-pin reinforcement. The numerical results show that the fracture load for delamination in the z-pinned DCB is greatly dependant on the fnctional pull-out force Pf. However, since the deformation of the z-pin is relatively small compared to sliding distance, the effects of debonding force and debonding length on the fracture resistance of the DCB are... 

The presence of Z-pins as the through-the-thickness reinforcement has been shown to result in dramatic increases in the apparent resistance to crack propagation under Mode I and Mode II loading conditions, in laboratory tests on standard unidirectional (UD) beam samples [2]. The Z-pin pull-out has been identified as the dominant energy micro-mechanism responsible for the resistance to delamination under Mode I conditions. The behaviour of individual Z-pins in pull-out from a UD-laminate has been characterised and modelled and the single Z-pin pull-out curves used as input into a 2D Finite Element (FE) model of delamination under Mode I [3, 4]. 

Specimens were strained in a push-pull mode by an Instron machine, Model TF-DM, which has cross head speeds from 0.05 to 0,5 cm/min and a load capability up to 10" kg. Details of the apparatus for the mechanical and electrical tests are reported elsewhere Only a brief description of the electrical portion is given here. The resistivity was measured by the typical four-probe dc method. A set of voltage leads were soft-soldered across the gauge length of the specimen surface. 

Soil—geotextile interaction in pull-out mode The geotextile length for slope and wall reinforcement is designed to provide anchorage beyond the potential failure surface. Such resistance can be modeled in the laboratory using a puU-out test. The pull-out resistance of the geotextile obtained in the test can be expressed as (Eq. [15.6]) ... 

Lin and Li [14] modelled the pull-out resistance of a slip hardening fibre by assuming a linear relation between the interfacial shear stress x and the slip A ... 

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