Compression buckling

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). 

Adherend stresses in weldbonded joints are lower and more uniform than those for comparable spot welded joints. This provides increased in-plane tensile shear and/or compressive buckling load-carrying ability for a given joint design. The presence of the spot weld provides enhanced out-of-plane load-carrying capability compared to adhesive bonding only. 

Ghorbanpour Arani et al. [49] 2007 FEM, cylindrical shell — 11.2 and 44.8 3.2 Pure axially compressed buckling and combined loading effects on SWCNT... 

Elastomers are used in the construction industry to control noise and shock and vibration and are used in many applications strictly to accommodate motion. In any application of elastomeric materials, the method of applying the elastomer can either help or hinder the desired end result. Basically, elastomers are used in situations of shear, compression, buckling, and bulk. The particular application will dictate which would be best. 

Axial compression buckling of the vertical wall Buckling of the vertical wall is by far the commonest failure mode in metal silos. The buckles can be huge or quite local, but all buckles should be treated as very serious because this mode of failure is often dramatically catastrophic. 

Under high internal pressures, a different form of axial compression buckle occurs, termed the elephant s foot because of its smooth flat squashed shape. Also, where a buckle occurs adjacent to a support, a buckle may develop in the local high stress fleld, needing a more careful evaluation (the force being transmitted may not be easily determined). 

FormabiHty limits can be extended by permitting small compression buckles to occur at the inner fibers and removing them later by hot sizing. The buckled region represents a condition of overforming and should be limited to the amotmt that can be effectively removed by hot sizing. 

Compressive buckling must also be considered, particularly if the bolted silo has corrugated walls or is constructed from aluminum. 

Check to ensure that the design can withstand compressive buckling. 

For polymers reinforced with continuous fibers, the situation can be reversed. Long, thin fibers support tensile loading much more effectively than they support compressive loading. Tensile stresses straighten and stiffen the fibers, whereas fibers loaded in compression buckle, with a concurrent loss of stiffiiess. Tlius, the tensile compliance in the direction of the fiber reinforcement should be less than the compressive compliance in the fiber direction. In the transverse direction, the compliance for tension and compression should behave more like pure resin, which has a higher compressive modulus. 

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