Mechanical Tests ISO 3537
Mechanical test equipments relating to the safety requirements for all safety glazing materials in a motor vehicle, whatever the type of glass or other material of which they are composed.
Ball Test
Purpose of test:
The purpose of this test is to determine whether the safety glazing material has a certain minimum strength and cohesion under impact from a small hard object.
Hardened steel ball
227 g, 38 mm
2260 g, 82 mm
Hardened steel ball, with a mass of (227 ± 2) g and a diameter of approximately 38 mm.Means for dropping the ball freely from a height to be specified, or means for giving the ball a velocity equivalent to that obtained by the free fall.
Supporting fixture：
composed of two steel frames, with machined borders, 15 mm wide, fitting one over the other and faced with rubber gaskets about 3 mm thick and 15 mm wide, of hardness 50 IRHD, determined in accordance with ISO 48. The lower frame rests on a steel box, about 150 mm high. The test piece is held in place by the upper frame, the mass of which is about 3 kg. The supporting frame is welded on a sheet of steel 12 mm thick, resting on the floor, with an interposed sheet of rubber, about 3 mm thick, of hardness 50 IRHD
Test piece： The test piece shall be a flat square with 300 mm
Procedure
Condition the test piece at the specified temperature for at least 4 h immediately preceding the test. Place the test piece in the fixture. The plane of the test piece shall be perpendicular, with 3°, to the incident direction of the ball. When necessary to retain the test piece in the fixture, it shall be clamped to ensure that the movement of the test piece during test will not exceed 2 mm at any point along the inside perhipery of the fixture.
The point of impact shall be within 25 mm of the geometric centre of the test piece for a drop height less than or equal to 6 m, and within 50 mm of the centre of the test piece for a drop height greater than 6 m. The ball shall strike the face of the test piece which represents the outside face of the safety glass when mounted on the vehicle. The ball shall be allowed to make only one impact.
Steel ball lifting device
Impact Height: 1m, 3m, 5m, 12m customizable
Steel ball releasing device
Electromagnet
Fragmentation Test
Purpose of test
The purpose of this test is to assess the ability of fragments of safety glazing material to cause injury in the event of racture.
Apparatus
- Instrument capable of causing the glazing material to break from the impacted surface, such as a hammer with a pointed head or an automatic punch.
- Mass: 75 g±0.3 g
- Radius of curvature of the point: 0.2 mm±0.05 mm
Procedure
Fix the test piece tightly on top of second test piece of the same shape and dimensions by means of transparent adhesive tape on the periphery, placing a piece of photographic paper between the test pieces.
The exposure of the photographic paper shall start not later than 10s after the impact and terminate not later than 3 min after it. Only the deepest lines, representing the initial fracture, shall be taken into consideration.
Head – Form Test
Purpose of test
The purpose of this test is to assess the minimum strength and cohesion of the safety glass under impact from a blunt, bulky object. If required, tests can be performed on whole windscreens.
Apparatus
- Head-form weight, with a spherical or semi-spherical head made of laminated hard wood covered with replaceable felt and with or without a cross-beam made of wood. Between the spherical part and the cross-beam, there is a neck-shaped intermediate piece and on the other side of the cross-beam, a mounting rod .
- Head Weight: 10kg
Head Size: 500mm*932mm
Impact height: < 1.5m
Supporting fixture
- The fixture is composed of two steel frames, with machined edges, 50 mm wide, fitting one over the other and faced with rubber gaskets about 3 mm thick, and (15 ± 1) mm wide, of hardness 70 IRHD, measured in accordance with ISO 48. The upper frame is pressed against the lower frame by at least eight bolts; the minimum recommended torque for M20 bolts is 30 N.m.
- Size: 1400mm*666mm*320mm
- Sample: 1100mm * 500mm
- Test height: less than or equal to 1.5 m
- Rubber pad: 15mm wide, 3mm thick, of hardness 70 Shore A
