What is impact load?

Answer 1

AnswerImpact Loading

• Generally when the strength of machine elements are considered it is assumed that the loading is static or applied gradually. This loading condition is often not the case, the loading may be cyclic requiring assessment for fatigue. Fatigue Index or it may involve impact or suddenly applied loads. When loads are applied suddenly and when the loads are applied as impact loads the resulting stresses induced in the machine elements are much higher than if the loads are applied gradually.

• It is normal practice to design machines such that impact loads are eliminated or reduced by inclusion of shock absorbers. Inclusion of low cost, mass produced, shock absorbers can virtually eliminate the increased loads resulting from impact loads.

• Most ductile materials have strength properties which are a function of the loading speed. The more rapid the loading the higher the tensile and ultimate strengths of the materials. . Two standard tests, the Charpy and Izod, measure the impact energy (the energy required to fracture a test piece under an impact load), also called the notch toughness.

• The detailed assessment of the strength of machine elements under impact loading regimes involves use of advanced techniques including Finite Element Analysis. Impact loads result in shock waves propogating through the elements with possible serious consequences. It is possible to complete relatively simply stress evaluation for suddenly applied and impact loads by using the principle of conservation of energy and assuming the materials considered respond to the loading elastically.

Answer 2

The effect on a structure or object of the forcible sudden contact - such as a blow or collision - with another (moving) body.