# What is allowable strength?

The

**allowable stress**or**allowable strength**is the maximum**stress**(tensile, compressive or bending) that is allowed to be applied on a structural material. The**allowable**stresses are generally defined by building codes, and for steel, and aluminum is a fraction of their yield**stress**(**strength**):A.

### What is allowable stress design?

Permissible

**stress design**(in USA construction more commonly called**allowable stress design**) is a**design**philosophy used by civil engineers. The designer ensures that the**stresses**developed in a structure due to service loads do not exceed the elastic limit.#### What is the meaning of ultimate load?

In aerospace engineering, the**ultimate load**is a statistical figure used in calculations, and should (hopefully) never actually occur. Strength requirements are specified in terms of limit**loads**(the maximum**loads**to be expected in service) and**ultimate loads**(limit**loads**multiplied by prescribed factors of safety).#### What is the limit load?

**Limit load**is the maximum**load**that a structure can safely carry. It's the**load**at which the structure is in a state of incipient plastic collapse. As the**load**on the structure increases, the displacements increases linearly in the elastic range till the**load**attains the yield value.#### How is working load limit calculated?

Vertical Hitch**Working Load Limit**X Number of Legs* X Sling Angle Factor = WLL at specified angle. The**Working Load Limit**for the sample sling above, in a 60° basket hitch would be**calculated**as follows: 500 lbs. (Vertical WLL) x 2 (num. of legs) x .866 (sling angle factor from table) = 866 lbs.

B.

### What is the difference between factored and Unfactored load?

A

**factored load**is a**load**multiplied by a certain**factor**designated by codes of practice to drermine the strength of a structural members such as reinforced concrete. Whereas the**unfactored loads**are used to meet the elastic or linear limit state (below the yield limit) of structural members.#### What is the meaning of axial load?

An**Axial load**is a force administered along the lines of an axis.**Axial loading**occurs when an object is loaded so that the force is normal to the axis that is fixed, as seen in the figure. Taking statics into consideration the force at the wall should be equal to the force that is applied to the part.#### What is allowable stress design?

Permissible**stress design**(in USA construction more commonly called**allowable stress design**) is a**design**philosophy used by civil engineers. The designer ensures that the**stresses**developed in a structure due to service loads do not exceed the elastic limit.#### What is the service load?

The**service load**is the best estimate of the actual**load**that a concrete member may be called on to support. The current way, Ultimate Strength. The design**load**is the**service load**increased by specified**load**factors in order to provide a factor of safety. Traditional Examples:**Service Load**= Dead**Load**+ Live**Load**.

Updated: 20th September 2018