37 results about "Second moment of area" patented technology

A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient's body. The filter element is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained. The filter element includes a mesh including strands, each strand having a diameter. The mesh includes at least one radiopaque strand and at least one non-radiopaque strand, and wherein each strand has an index of wire stiffness EI, where EI is the mathematical product of the Young's modulus (E) and the second moment of area (I), and wherein the largest EI of a strand is no more than five times the smallest EI of a strand.

An electrically insulating cross-arm for a tower for high-voltage power networks. The cross-arm includes an insulating structural member for attachment to the tower body and to support a conductor cable. The insulating structural member comprises a solid rigid spine extending along a long axis having cross sectional profile, normal to the long axis, having a second moment of area of its cross sectional profile about every axis normal to the long axis and dissecting its centroid has a value of A²/2π or more, where A is the area of the cross sectional profile. The structural member provides resistance to bending and compressive buckling and allows conductors to be safely supported at reduced tower height. T and Y shaped cross sections provide water run-off and inhibition of organic growth. The structural members are also generally useful as insulator members in high voltage power networks.

A method of increasing concentricity in use of a spiral hairspring mechanical timepiece; the hairspring having an inner terminal end portion for engagement with a collet, an outer terminal end portion for engagement with a stud, a first limb portion extending from the inner terminal end portion towards the outer terminal end portion, and a stiffening portion positioned at the outer turn of the hairspring and having a cross-sectional second moment of area different to that of the first limb portion such that bending stiffness of the stiffening portion has a greater bending stiffness than the single limb portion. The method includes modifying cross-sectional second moments of an area of the first limb portion and the stiffening portion by minimizing a cost function throughout the amplitude of the rotation of hairspring in use, the cost function being correlated to the net concentricity of the hairspring.

An opening radial dimension is set as a radial direction permissible dimension K of the metal coil as expressed by the following equation or lower.

Wherein: K is a radial direction permissible dimension at the load action point position in mm; Yp is a yield stress of the metal sheet, in kgf/mm²; Z is a section modulus of the metal sheet, in mm³; R=(a metal coil radius r)−½(the plate thickness t of the metal sheet), in mm; E is a Young's modulus of the metal sheet, in kgf/mm²; I is a second moment of area of the metal sheet in mm⁴; and Θ is an angle in radians about the axis of the metal coil from the load action point to the nearest restraining roll along a rewind direction of the metal coil.

Parabolic Mirror. The mirror includes a flexible material with a reflective surface and a rear surface. A flexible band is in contact with the rear surface of the flexible material. The bending stiffness of the band as a function of distance along its length is selected so that the band and the flexible material in contact therewith assume a parabolic shape when ends of the band are moved toward one another. In a preferred embodiment, the bending stiffness of the band is achieved by controlling the second moment of area of the band along its length. The second moment of area may be adjusted by altering the width of the band along its length or by altering the thickness of the band along its length, or a combination of the two.

Shock absorbing structure (10, 10") for a vehicle comprising a side sill (2) comprising two chassis frame side members (4, 4") which together support a bumper beam (6, 6"), said shock absorbing structure comprising said bumper beam and an absorber (7, 7") interposed between each chassis frame side member and said bumper beam, said absorber having a working part (71) intended to deform in the event of an impact under the effect of a load below the limit load beyond which said chassis frame side member undergoes plastic deformation, said absorber being a section piece of which one end (72) is inserted inside the open end (5, 5") of said chassis frame side member and fixed thereto, characterized in that said absorber is an extruded aluminium alloy section piece of which the part not inserted inside said chassis frame side member or inside said bumper beam, which corresponds to said working part, has a length greater than 5 times its radius of gyration defined by formula (I), where I is the quadratic moment and S the cross-sectional area of said section piece, said cross section being such that, under the effect of a substantially frontal impact, said working part is able to deform in crumpling over a length such that the longitudinal crush distance is greater than 4 times said radius of gyration.

The invention provides a floating air cushion support platform, which is mainly composed of a platform main body, a truss and ballast. The platform main body includes a buoyancy chamber, an air chamber, an air chamber partition, a central well and a damping apron. Below the platform, the main body of the platform and the ballast are connected by trusses, and the waterline is inside the main body of the platform. The buoyancy chamber provides the buoyancy required by the system, and increases the water surface area through the buoyancy chamber; the air chamber partition divides the air chamber into multiple independent units, and increases the section moment of inertia of the air chamber through the air chamber partition; the damping apron The viscous damping of the platform is increased; the ballast arranged below can lower the center of gravity of the system, and can also act as a heave plate, reducing the heave response of the system. Relying on the barge-type support platform, this platform has simple structure, convenient construction and low cost. By introducing the design of air cushion, it solves the problem of large motion response of ordinary barge-type floating structures under the action of waves.

A treatment device includes a first grip member having an elongated shape, and a second grip member which is displaced with respect to the first grip member to grip the biological tissue between the first grip member and the second grip member. The second grip member includes a grip section that comes into contact with a biological tissue as a gripping target. I/A² of the grip section is maximum at the proximal end, and/or Z/A^3/2 of the grip section is maximum at the proximal end, where I is a second moment of area, Z is a section modulus, and A is a cross-sectional area calculated based on an axis perpendicular to a straight line passing through a center of gravity of the first grip member and a center of gravity of the second grip member in a cross section perpendicular to a longitudinal axis of the grip section.

The invention relates to a method for obtaining the bending equivalent stiffness of a skin stiffened cylindrical shell structure. The method comprises the following steps: step 1, the skin elasticity modulus, stringer torsional elasticity modulus, skin shell diameter and skin thickness of the skin stiffened cylindrical shell structure are collected respectively, wherein collected stringers are of m categories totally, and then the number and sectional area of the stringers in each category are collected; step 2, the total equivalent thickness of the stringers is obtained; step 3, the total equivalent thickness and total area equivalent moment of inertia of the skin stiffened cylindrical shell structure are obtained; step 4, optimization factors of second moment of area are obtained; step 5, modified second moment of area is obtained; step 6, the total actual bending stiffness of the skin stiffened cylindrical shell structure is obtained. The method for obtaining the bending equivalent stiffness of the skin stiffened cylindrical shell structure solves the problem that the deviation of the bending stiffness causes the situation that errors of bending frequency are gradually increased along with the increase of orders, and can be used for obtaining the bending stiffness of the skin stiffened cylindrical shell structure reasonably, easily and quickly.

A clip may include an anchor portion having a plurality of flexible strips and at least one support strip. Each of the flexible strips is integrally connected to the at least one support strip only via a connecting portion corresponding to a distal end portion of the anchor portion and a connecting portion corresponding to a proximal end portion of the anchor portion. When the anchor portion is pushed into an insertion hole formed in a subject member, the anchor portion is inserted into the insertion hole while each of the flexible strips are flexed toward a longitudinal axis of the anchor portion. Each of the flexible strips is formed such that the difference between a second moment of area of the anchor distal end side connecting portion and a second moment of area of the anchor proximal end side connecting portion is 0-15%.

The invention discloses a special-shaped rectangular pipe. The pipe with a function of supporting is applied to commercial vehicles and produced by means of online continuous cold-bending process and single-pipe bending process. The problems of simple structure, small second moment of area, limited section performance, excessive machining and welding procedures, low yield and complexity in installation process of existing normal sections are solved. The pipe comprises a steel plate integrally forming a 9 shape by cold bending, a weld seam (6) is reserved at the butt joint of the steel plate, and the cross section of the steel plate is in the 9 shape. A cold-bending pipe welding set is adopted for continuous roll bending, online welding shaping, online saw cutting, single-plate bending and offline welding shaping of a bending machine.

A sunlight concentrating apparatus includes a plate-like reflecting part, with an upper reflection surface extending in an axial and a width direction, and a lower surface having a central linear region fixed to a main shaft part. A pair of bending mechanisms bend the reflection surface by moving opposite end portions in a central normal direction in accordance with a rotation of the main shaft part. The reflecting part includes a mirror plate and a support plate thereon. In the support plate, the ratio between the distance in the width direction from each end portion in the width direction and the second moment of area at this distance is constant between the end portion and the central linear region, allowing the reflection surface to be bent in an are shape.

The invention discloses a special-shaped rectangular pipe. The pipe with a function of supporting is applied to commercial vehicles and produced by means of online continuous cold-bending process and single-pipe bending process. The problems of simple structure, small second moment of area, limited section performance, excessive machining and welding procedures, low yield and complexity in installation process of existing normal sections are solved. The pipe comprises a steel plate integrally forming an OM shape by cold bending, a weld seam (10) is reserved at the butt joint of the steel plate, and the cross section of the steel plate is in the OM shape. A cold-bending pipe welding set is adopted for continuous roll bending, online welding shaping, online saw cutting, single-plate bending and offline welding shaping of a bending machine.

The invention relates to a backbone rail (1) for a roller coaster. The backbone rail (1) comprises two rail pipes (2, 4) designed for vehicles to travel upon, and at least one, particularly main load-bearing backbone pipe (6) not designed for vehicles to travel on, whose second moment of area is greater than the second moment of area of the rail pipes (2, 4), wherein rail pipes (2, 4) and backbonepipe (6) are connected to each other section- by-section by means of stiffening bulkheads (10), whereby at least one bulkhead (10) has the following features: A transverse cross member (8), which extends in the orthogonal direction and connects the rail pipes (2, 4) with each other, and bulkhead plates (12, 14), connecting at least one rail pipe (2, 4) with the backbone pipe (6), wherein at leastone bulkhead plate (12, 14) is designed as a longitudinal bulkhead plate, whose main plane of extension extends perpendicular to the bulk- head plane, and which is attached to the backbone pipe (6) in such a way that it runs tangentially into the backbone pipe (6). In addition, the invention relates to a roller coaster arrangement with such a backbone rail.

A treatment device includes a treatment portion, a transmission portion and a moment shift portion. The treatment portion transmits ultrasonic vibration. The length of the treatment portion is shorter than ¼ of a wavelength of the ultrasonic vibration. The transmission portion has one end at a node position where the first generated node from the distal end of the treatment portion appears, and is located closer to a proximal side than the node position. The length of the transmission portion is ¼ of the wavelength. The moment shift portion is located between the treatment portion and the transmission portion. An average of I1/A12 is greater than an average of I2/A22, where I1 is the second moment of area and A1 is a sectional area in the treatment portion, and I2 is the second moment of area and A2 is a sectional area in the transmission portion.