Tensile-compressive loading

Figure 7.22 Tensile-compressive loading occurs on a flexural specimen...

Hart-Smith (reference 5.26) has presented the situation where the joint is loaded by tensile or compressive and in-plane shear loadings simultaneously. Joint failure will occur when the bondline displacement resultant caused by these actions exceeds the capacity of the adhesive. If the tensile (compressive) loading develops a maximum bondline displacement of ta(yt,c)max and the shear loading induces an orthogonal displacement of ta(ys)max at the same end of the joint, the displacement at failure is ... 

Shear stresses cause sliding in an element of material as shown in Fig. 1(a). All shear tests are variants of either an overlap or a torsional joint and these are illustrated schematically in Figs. 1(b) and (c). The shear in the first is induced by transfer of the tensile/compressive load from one substrate to the other, while in the second it is caused by transfer of torsional loads from one substrate to the other. The tests have been grouped according to the manner in which the shearing has been induced. 

For load capacity, e.g., under flexural and tensile/compression load, Eq. 1.61 applies ... 

The residual compressive deformations of the specimens were measured for the tensile-compressive loading. Their values were assumed to be equal to a distance from the maximum compressive stress point in a cycle to the tangent line corresponding to the ascending tensile branch of the stress-deformation curve in the direction of axis (Fig. 4). A slow... 

A model of the post-peak cyclic behaviour of the concretes investigated for the tensile-tensile and the tensile-compressive loading is proposed. The average stress-total deformation curves are split into two parts the ascending parts in which a tmique relation exists between the stress and the strain that consists of an elastic ccanponent and an iirreversible one ... 

Figure 5. Model for the cyclic loading the pre-peak range (E) the post-peak range for the tensile-tensile (A) and for the tensile-compressive loading (B).

The reference sample in form of a cylinder or bar with probe placed on top of it, is subject to tensile or compressive loading using strength machine ( Instron type). 

Most components of the strength tensors are defined in terms of the engineering strengths already discussed. For example, consider a uniaxial load on a specimen in the 1-direction. Under tensile load, the engineering strength is Xj, whereas under compressive load, it is (for example, Xg = -400 ksi (-2760 MPa) for boron-epoxy). Thus, under tensile load. 

Laminated composite plates under in-plane tensile loading exhibit deformation response that is both like a ductile metal plate under tension and iike a metai plate that buckles. That is, a composite plate exhibits progressive faiiure on a layer-by-layer basis as in Figure 4-34. Of course, a composite plate in compression buckles in a manner similar to that of a metal plate except that the various failures in the compressive loading version of Figure 4-34 could be lamina failures or the various plate buckling events (more than one buckling load occurs). 

The classic way that we perform force versus deformation measurements is to deform a sample at a constant rate, while we record the force induced within it. We normally carry out such tests in one of three configurations tensile, compressive, or flexural, which are illustrated in Fig. 8.1. We can also test samples in torsion or in a combination of two or more loading configurations. For the sake of simplicity, most tests are uni-axial in nature, but we can employ bi-axial or multi-axial modes when needed,... 

The mechanical properties of a material describe how it responds to the application of either a force or a load. When this is compared to an area, it is called stress, another term for pressure. Three types of mechanical stress can affect a material tension (pulling), compression (pushing), and shear (tearing). Figure 15.27 shows the direction of the forces for these stresses. The mechanical tests consider each of these forces individually or in some combination. For example, tensile, compression, and shear tests only measure those individual forces. Flexural, impact, and hardness tests involve two or more forces simultaneously. 

Due to the complex mixed-mode nature of composite delamination, no closed form solutions have been developed yet to express the influence of governing parameters that control the edge delamination behavior. Under tensile loading, delamination is normally preceded by a number of transverse cracks, particularly in the 90° plies. Because of the presence of these cracks, the location of delamination is not unique as in the case of compressive loading, which invariably results in gross buckling of the laminate. The path of delamination along the axial direction varies... 

Orient fibers in direction of loading For tensile and compressive loads along the axial direction of the cylinder, wind helical plies at the lowest possible angle to the shaft axis for in-plane shear loads align fibers at 45 to the shaft axis... 

Some plastic materials have different tensile and compressive characteristics. For example, polystyrene is tough under compressive load but very brittle in tension. However, for most elastoplastic materials, the stress-strain curves in compression are the same as in tension. Hence, the deformation properties of these materials in tension may also be applied to those in compression, which is of great interest to gas-solid flows. 

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