Impact Strength


Also found in: Dictionary, Thesaurus, Medical, Financial.
Related to Impact Strength: hardness

impact strength

[′im‚pakt ‚streŋkth]
(mechanics)
Ability of a material to resist shock loading.

Impact Strength

 

the ability of a material to absorb mechanical energy in the process of deformation and fracture under impact loading. The term “impact strength, ” as well as the term “impact energy, ” is also applied to the amount of energy absorbed before fracture.

To determine impact strength, a bending impact test is commonly used. The specimen in this case has a prismatic bar shape, and a transverse notch is cut in one side of the specimen. The impact strength is regarded as the work required for the fracture of the specimen. In the USSR the work is generally referred to the cross-sectional area of the specimen at the base of the notch and is expressed in joules per square meter, newton-meters per square meter, or kilogram-force-meters per square centimeter.

Impact strength is one of the most important strength characteristics of a metal. When the test temperature is lowered over a series of tests, a sharp drop in impact strength indicates the brittle temperature of the material. Reliable performance of the material is possible only at temperatures above the brittle temperature.

In another type of bending impact test that is sometimes used, a small fatigue crack is produced in advance at the base of the notch; the crack is 1.5 mm in length. In this case a measurement is made of the specific work required for fracture of the specimen. Compared with the impact strength as measured in the first type of test described, the impact strength measured in this way provides a more sensitive characterization of the brittleness of high-strength materials. (See alsoMECHANICAL PROPERTIES OF MATERIALS.)

S. I. KISHKINA

impact strength, impact energy

The amount of energy required to fracture a material; a measure of the material’s resistance to mechanical shock.
References in periodicals archive ?
Samples for impact strength test were fabricated based on international organization for standardization (ISO 1567) with rectangular shape 50 mm x 6 mm x 4 mm in size, [24] while samples for transverse strength and modulus of elasticity test were fabricated in 65 mm x 10 mm x 2.5 mm according to ADA Specification No.
Impact strength ranges from 1.1 X [10.sup.3] J/[mm.sup.2] to 2.3 X [10.sup.3] J/[mm.sup.2] with a mean of 1.6 X [10.sup.3] J/[mm.sup.2] (Figure 1).
The average impact strength of the control samples (bonded without rotation of the samples from each other) amounted to 17.85 [+ or -] 3.21 kJ/[m.sup.2] and the samples in which the upper element was rotated against the lower one by approximately 5.89 [+ or -] 0.68 kJ/[m.sup.2].
2: Effect of wheat straw pretreatment on Impact Strength and Compressive Strength of experimental pellets of Particle Board.
Therefore, the phase morphologies of both 80/20 and 60/40 PP/POE blend samples collected along the extruder were observed by SEM and used to explain the different profiles of the impact strengths of both blends along the extruder with two different mixing types.
6% for 5.56% aluminum alloy and 9% for 4.51% aluminum alloy) failed to improve the impact strength of the alloy significantly, plausibly because a small percentage of dendrites was unable to form a continuous dendritic framework so a fracture could always proceed through the weak zinc-aluminum eutectic.
In spite of high strength, wear and heat resistance, and ease of fabrication and processing for PA6, however, its impact strength, dimensional stability, and barrier properties to moisture are very poor, which limits its application in many fields.
Specimens were polished stored in distilled water for 24 hours prior to experiment.After 60 days of immersion the specimens were tested for impact strength with impact strength tester.
(1, 2, 3) In order to achieve the desirable impact strength characteristic of poly methyl methacrylate, a study can be conducted by reinforcing it with E glass fibers since it is a most commonly used fiber for acrylic reinforcement due to its higher mechanical properties, low susceptibility to moisture absorption, resistance to chemicals, thermal stability and high melting point.