Ultimate load

Post-installed bolts will be required at times for attachment of equipment which may be subjected to large accelerations during a blast. Expansion anchors should be avoided for most blast design applications unless the load levels are low. Typically "wedge" type anchors are qualified for dynamic loads although most of these ratings are for vibratory loads and are based on cyclic tests at low stress levels. These should only be used where ultimate loads are less than the rated capacity with a margin of safely. Epoxy anchors have shown excellent dynamic capacity and may be considered for critical applications. 

In a strict sense, an advanced analysis" is one in which the nonlinear geometric and material effects are accounted for in the analysts of the structure as a whole in determining its ultimate load carrying capacity. In addition, effects of local as well as overall global instability are considered such that it is not necessary to evaluate individual members subsequent to the completion of the advanced analysts. In other words, all the appropriate limit state, design code requirements are incorporated into the analysts (White 1993, Chen 1994). 

When an anticipated load on the downstream side will not develop for several months after installation of a valve, fit to the valve a reduced-area disk sized to handle the present load. When the load increases, install a full-size disk. Size the valve for the ultimate load, not the reduced load. 

Strength properties are time dependent. The load that timber can sustain without failure decreases with time. If the short-term ultimate load in the 5-minute static bending test is taken as the reference point, then wood will fail, on average, at about 66% of that load after 1 year, at 62% after 10 years and at 56% after about 27 to 200 years depending on the curve used to fit the data there is a dearth of long term experimental evidence (>10 yr). 

From the above equation, a break load (an ultimate load) for a standard Trex board equals to 509 lb. This would translate to an ultimate uniformly distributed load of 1667 Ib/ftl... 

P = ultimate load, in lb (for flexural strength) or a load (for flexural modulus) L = support span, in in. ... 

As it will be shown later in this chapter, flexural strength and modulus, and the ultimate load (load at break, or load at failure) are all proportionally dependent on the moment of inertia. Thus, it can be concluded right away that a break load of a GeoDeck board, whatever its length would be, for Heavy Duty board will be 240% (140% higher) of that for Traditional board or Tongue and Groove board (on a deck). 

The readout of the procedure is the load and the respective deflection until failure. The load at which the specimen fails is called the ultimate load, or load at failure. 

For the maximum bending stress, which occurs at the ultimate load (point of rupture),... 

Note of the author That is why center-point loading is the most severe one among the three modes of loading, and ultimate load (break-point load) for center-point... 

For the maximum bending stress, which occurs at the ultimate load, that is, at the moment of break (point of rupture), for third-point load (see Eq. (7.28))... 

Material Width (in.) Depth (in.) Deflection at break (in.) Maximum strain in the outer surface (%) Ultimate load (lb) Flex strength (psi)... 

The table shows that the flexural strength values vary for different profiles in a rafher narrow range of 11%. There is not any correlation of flex strength with a shape, span, moment of inertia, ultimate load, and so forth. Apparently, the variations result from deviations of the profile from their theoretical behavior when stressed and strained. 

As it was shown above, center-point loading is the most severe among the three modes of loading—center-point, third-point, and quarter-point loading. Theoretically, ultimate load (break-point load) for center-point load should be 1.5 times lower compared to third-point load, when the same materials and profiles are fesfed. In reality, there might be some slight deviations from this coefficient due to anisotropicity of materials, too short support span (i.e., a noticeable effect of shearing compared to flexural), nonflat position of a specimen, and so forth. 

Table 7.16 shows that for most cases the ratio between ultimate loads for center-point load and one-third point load is not exactly 1.5, as should follow from Eq. (7.20) and (7.26). It is around 1.50 only for square cross-sectional pickets. For all flat profiles (including an almosf oval-shaped handrail profile), fhe ratio is equal to 1.38 + 0.04 (an average for seven profiles). Apparenfly, this deviation from the theoretical figure of 1.5 is a reflection of anisotropic properties of the tested composite materials. 

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