Turbomachine rotary fan blade, fan, and turbomachine provided therewith

A blade for a turbomachine rotary fan, the blade comprising a body having an upstream edge and a downstream edge, between which the body extends along a first longitudinal direction, an extrados and an intrados, between which the body extends along a second thickness direction, which is transverse to the first direction, a blade root and an upper blade tip edge, between which the body extends along a third height direction, transverse to the first longitudinal direction and to the second thickness directions, a function of the blade root being to be fixed to a longitudinal rotary fan hub,

• the blade comprising a predetermined breaking zone, which extends from the upstream edge over a determined non-zero length along the first longitudinal direction and which extends from the upper blade tip edge over a determined non-zero height along the third height direction, wherein
• the body is made of a composite material comprising a fiber reinforcement obtained by three-dimensional weaving of warp strands extending at least along the third height direction and of first weft strands extending at least along the first longitudinal direction, and a resin matrix in which the fiber reinforcement is embedded,
• the first weft strands comprise second weft strands, which have at least one discontinuity in or in proximity to the predetermined breaking zone and which are configured so that the predetermined breaking zone is partially detached in the presence of tangential friction extending in the second thickness direction against the upper blade tip edge,
• the determined non-zero height of the predetermined breaking zone being less than 3% of an aerodynamic stream height of the blade, defined from the upper blade tip edge to an aerodynamic stream starting point of the blade, which is located at a distance from the blade root and which is intended to be in contact with an inter-blade platform along the third height direction.

A blade for a turbomachine rotary fan, the blade comprising a body having an upstream edge and a downstream edge, between which the body extends along a first longitudinal direction, an extrados and an intrados, between which the body extends along a second thickness direction, which is transverse to the first direction, a blade root and an upper blade tip edge, between which the body extends along a third height direction, transverse to the first longitudinal direction and to the second thickness directions, a function of the blade root being to be fixed to a longitudinal rotary fan hub,

• the blade comprising a predetermined breaking zone, which extends from the upstream edge over a determined non-zero length along the first longitudinal direction and which extends from the upper blade tip edge over a determined non-zero height along the third height direction, wherein
• the body is made of a composite material comprising a fiber reinforcement obtained by three-dimensional weaving of first warp strands extending at least along the third height direction and of first weft strands extending at least along the first longitudinal direction, and a resin matrix in which the fiber reinforcement is embedded,
• the first warp strands comprise second warp strands, which have at least one warp strand discontinuity in or in proximity to the predetermined breaking zone,
• the first weft strands comprise second weft strands, which have at least one weft strand discontinuity in or in proximity to the predetermined breaking zone,
• the first warp strands and the first weft strands being configured so that the predetermined breaking zone is partially detached in the presence of tangential friction extending in the second thickness direction against the upper blade tip edge,
• the determined non-zero height of the predetermined breaking zone being less than 3% of an aerodynamic stream height of the blade, defined from the upper blade tip edge to an aerodynamic stream starting point of the blade, which is located at a distance from the blade root and which is intended to be in contact with an inter-blade platform along the third height direction.