Provided are a laser-welded structure and a laser welding method for a cover and a housing ensuring high reliability and suppressing changes in characteristics due to burrs protruding into a subpassage of the flow sensor. To this end, this flow sensor is provided with a housing, a cover, a circuit chamber sealed between these and housing electronic components or wiring, and a subpassage through which the fluid flows that is to be sensed, and is characterized in that there are projections provided on both ends of the joining section of the cover where the housing and the cover are laser-welded, and the height of the projection on the subpassage side is greater than the height of the projection on the side opposite of the subpassage.

A method for forming butt joints between thermoplastic members by resistive implant welding. A tongue is formed on one member to be joined and a complementary groove is formed in the other member. A resistive implant is placed between the tongue and the groove which are then pressed together by an applied pressure. An electric current is run through the resistive implant to melt a portion of the thermoplastic material of both the tongue and groove, and the melted plastic intermingles through the implant. When the electric current is removed, the plastic cools, forming a weld.

A lightweight support structure includes a composite sandwich panel having a first face sheet and a lightweight core attached to the face sheet and an essentially rotationally symmetric cut-out extending through the first face sheet and into the lightweight core. The cut-out has an essentially rotationally symmetric inner cut-out and outer cut-out arranged essentially concentric with respect to each other, providing for a support there between. The support has a core support cut from the lightweight core and a support face sheet disc on top, cut from of the first face sheet. A rotationally symmetric insert is fitted into the cut-out for load application and/or anchorage of various components into and onto the sandwich panel.

A curved composite structure, comprises at least two curved composite panel segments joined together. Each of the panel segments includes a fluted core sandwiched between first and second facesheets. A layer of adhesive is used to rigidly bond the panel segments together.