Abstract: A technique for evaluation of the strength of a spot welded portion of a panel is provided. A stress value at the welded portion of the panel is calculated by a stress analysis according to a FEM using the elements, and then the strength of the welded portion is evaluated based on the stress value at the welded portion. A portion in the proximity of the spot welded portion is divided, with a central portion of the spot welded portion registered with a nodal point of the elements, into a central element and plural concentric ring-like elements from the center side provided by the central portion of the spot welded portion. Thereafter, the plural concentric ring-like elements are individually divided in a circumferential direction each into a plurality of portions to form the elements. Then, the strength is evaluated based on the stress value of the second ring-like element.

Abstract: The invention provides a technique for evaluation of a spot welded portion by which the strength of a panel. In the evaluation method, a stress value at a welded portion of the panel is calculated by a stress analysis according to a FEM using the elements, and then the strength of the welded portion is evaluated based on the stress value at the welded portion. Particularly, a portion in the proximity of the spot welded portion is divided, with a central portion of the spot welded portion registered with a nodal point of the elements, into a central element and a plurality of concentric ring-like elements including first and second ring-like elements from the center side provided by the central portion of the spot welded portion. Thereafter, the plural concentric ring-like elements are individually divided in a circumferential direction each into a plurality of portions to form the elements. Then, the strength is evaluated based on the stress value of the second ring-like element.

Abstract: A headlamp for vehicles has a lens and a parabolic reflector which are made of synthetic resin and which are joined together by heat. A composite, light scattering reflector for scattering or spreading the light to be concentrated to the upper and central portion of the lens to an extend that no glare is generated, is arranged at the upper and central portion of the parabolic reflector. The composite reflector may be integrally formed with the main parabolic reflector, or may be a separate element joined to the main parabolic reflector.

Abstract: In an automotive head lamp, an auxiliary reflector made of heat-resisting synthetic resin is integrally provided in the center portion of a reflector made of synthetic resin. The heat-resistant auxiliary reflector encircles the bulb.