A method of press bending a circular arc to a straight edge corner weld

Abstract

A method for bending a circular arc to a straight edge corner welding, which adopts a transition plate to transition the circular arc bending plate to a straight edge corner welding form, so that the inner bottom plate, the inner shell and the longitudinal girder structure are longitudinally continuous, the gusset plate, the transition plate and the inner bottom plate are sequentially butt welded, and the longitudinal girders are continuously welded with the gusset plate, the connecting plate and the inner bottom plate. The transition circular arc plate gradually transitions the circular arc of the gusset plate to the straight edge corner welding seam, and there is no hard point and misalignment structure in the whole structure transition process. Through the transition form of the variable circular arc radius, the transition of the continuous bulkhead structure from the circular arc bending form to the corner welding form is effectively realized, and the tightness and continuity of the key node position of the continuous bulkhead structure are ensured. The design scheme of the circular arc transition to the straight edge avoids the narrow space that cannot be aligned, has the characteristics of convenient construction, continuous structure, material saving, high reliability and reasonable structure design, and can effectively reduce the number of structural members and the structure weight.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding and design, and specifically relates to a method for transitioning from bending an arc to straight corner welding. Background Technology

[0002] In ship structural design, bends exist at the connections between the inner hull and the lower sloping hull (referred to as the upper bend) and between the lower sloping hull and the inner bottom plate (referred to as the lower bend). At these bends, if a straight-edge fillet weld is used for connection (such as...),... Figure 1 As shown in the image, this fillet weld typically requires full penetration and structural flaw detection and tightness testing. To reduce the workload of welding, flaw detection, and tightness testing, most upper and lower corners use a rounded bending plate structure to avoid fillet welds at the corner points.

[0003] Typically, the cargo hold uses a curved plate design, while the engine room and bow use a corner weld design. Since the cargo hold, engine room, and bow have different designs and no corresponding structure, the curved plate needs to be converted to a straight corner weld design for alignment with the engine room and bow structure.

[0004] To convert the curved bending plate to a straight fillet weld, the common method is to interrupt the longitudinal bulkhead and bulkhead longitudinal skeleton at the transverse frame, and use two connection methods for the transverse frame: curved bending plate and straight fillet weld (e.g.) Figure 1 (As shown). Although this design completes the transformation from a curved bending plate to a fillet weld, it has the following three drawbacks:

[0005] 1. It causes discontinuity in longitudinal strong components, reducing the overall longitudinal strength of the ship.

[0006] Second, at the corner points of the front and back of the horizontal frame, some structures are misaligned, creating narrow spaces and hard spots that cannot be avoided.

[0007] Third, the need to add end elbow plates at the discontinuities of the longitudinal ribs at the front and rear of the transverse frame for transition and stress diffusion will increase the number of a large number of useless components and increase the structural weight.

[0008] Therefore, how to complete the conversion of the bending plate to the fillet weld while ensuring the continuity of the longitudinal bulkhead, and reduce the number of useless structures on the ship, is the technical problem that this patent needs to solve. Summary of the Invention

[0009] To address the aforementioned problems, this invention provides a method for transitioning from bending an arc to welding a straight corner, aiming to improve overall longitudinal strength, ensure structural alignment, and avoid structural hard spots. The technical solution adopted is as follows:

[0010] A method for transitioning from a bent arc to a straight corner weld: the hull bottom plate (5) and the inner shell (1) are connected at the longitudinal girder (7) by a bent arc plate (2). The bent arc plate is a rectangular plate, and its center is bent and recessed before being welded to the inner bottom plate and the inner shell respectively. The radius of the bent arc plate is R1, 100mm. <R1<400mm。

[0011] The bent arc plate extends forward along the longitudinal girder. When it passes the transverse frame (8), the transverse frame breaks, and the bent arc plate becomes continuous with the longitudinal girder. After passing the transverse frame, the inner bottom plate, inner shell, and bent arc plate continue to extend forward for a length A, 15mm. <A<100mm。

[0012] After the inner shell extends by length A, it forms a seam with the large elbow plate. After the bent arc plate extends by length A, it forms a seam with the transition arc plate. After the inner bottom plate extends by length A, it forms a seam with the inner bottom plate. The transition arc plate is an isosceles triangular plate. After the center of the plate is bent and recessed, it is connected to the large elbow plate and the inner bottom plate respectively through connecting plates. The radius of the transition arc plate is R2. The width of the connecting plate is C. One side of the transition arc plate is welded to the large elbow plate through a connecting plate, and the other side is welded to the inner bottom plate through another connecting plate.

[0013] The bottom edge of the transition arc plate meets the bending arc plate to form a plate seam, and the width of the bottom edge of the transition arc plate is the same as the width of the bending arc plate. The initial value of R2 is the same as that of R1.

[0014] The length of the transition arc plate is B. The large elbow plate forms a fillet weld (12) with the inner bottom plate from the end of the transition arc plate toward the bow. In the area of ​​the fillet weld, the inner floor extends outward by a length E.

[0015] In the above-mentioned method of transitioning from a curved arc to a straight corner weld, the large elbow plate and the connecting plate are joined to form a first weld (10), and the inner bottom plate and the transition plate are joined to form a second weld (11). The distance between the first weld and the edge of the transition arc plate is C, and the distance between the second weld and the edge of the transition arc plate is C.

[0016] The aforementioned method for transitioning from a bent arc to a straight corner weld is further characterized by, 80mm <C<150mm。

[0017] Furthermore, in the aforementioned method of transitioning from bending an arc to welding a straight corner, the inner shell and the large elbow plate are tilted at 45° relative to the inner bottom plate.

[0018] The above-mentioned method for transitioning from a bent arc to a straight corner weld can be further improved to 80mm. <B<150mm。

[0019] Furthermore, in the above-mentioned method of transitioning from a bent arc to a straight corner weld, after the transition plate is welded to the large elbow plate and the inner bottom plate, an arc-shaped weld is used at the end of the transition plate to connect the first weld and the second weld, forming a continuous weld.

[0020] Furthermore, in the above-mentioned method of transitioning from bending an arc to welding a straight corner, the length E is 50mm.

[0021] This invention addresses the shortcomings of traditional designs where the inner shell is discontinuous by proposing a scheme where the longitudinal bulkheads of the inner shell are continuous at transition points, thereby improving the overall longitudinal strength of the structure. The continuous bulkhead structure reduces the number of welds at discontinuous locations in the original design, reducing the workload of flaw detection and watertightness testing, and ensuring structural continuity and watertightness.

[0022] The transverse frame gradually transitions from an arc shape to a fillet weld, avoiding the hard spots of traditional designs, improving the structural layout, and reducing local stress. In this design, the longitudinal bulkheads and longitudinal ribs are continuous, reducing the number of end elbows at discontinuities and thus reducing the number of components.

[0023] Considering the technical requirements of transitioning from a curved edge to a straight edge, a transition plate was used to transition the curved bent plate to a straight-edge fillet weld. This transition scheme achieves longitudinal continuity in the inland, bulkhead, and longitudinal girder structures. The lower inclined plate, transition plate, and straight-edge bulkhead are sequentially butt-welded, and the fillet welds between the longitudinal girder and the lower inclined plate, transition plate, and straight-edge bulkhead are continuous. The curved edge of the transition plate gradually transitions the curved edge of the lower inclined plate to the straight-edge fillet weld. The entire structural transition process is free of structural hard points and misalignments.

[0024] This transition structure effectively facilitates the transition of the continuous bulkhead structure from a bent arc form to a straight-edge corner weld form, ensuring the tightness and continuity of key nodes in the continuous bulkhead structure. The aforementioned arc-to-straight-edge transition design is characterized by convenient construction, structural continuity, material saving, high reliability, and a rational structural design. It is suitable for all arc-to-straight-edge transition structural designs and meets various industry specifications and standards. Attached Figure Description

[0025] Figure 1 It is a schematic diagram of a ship;

[0026] Figure 2 yes Figure 1 Enlarged view of the square frame;

[0027] Figure 3 yes Figure 2 Left view diagram;

[0028] Among them, 1 - inner shell, 2 - bent arc plate, 3 - transition plate, 4 - transition arc plate, 5 - inner bottom plate, 6 - large bracket, 7 - longitudinal girder, 8 - transverse frame, 9 - plate seam, 10 - first weld seam, 11 - second weld seam, 12 - fillet weld. Specific implementation mode

[0029] The present invention will be further described in conjunction with the attached drawings.

[0030] A method for transitioning from a bent arc to a right-angle corner welding. The inner bottom plate 5 of the ship's hull and the inner shell 1 are connected by a bent arc plate 2 at the longitudinal girder 7. The bent arc plate is a rectangular plate, and after being bent and recessed at the plate center, it is welded to the inner bottom plate and the inner shell respectively. The radius of the bent arc plate is R1, where 100mm < R1 < 400mm.

[0031] The bent arc plate extends straight forward along the length direction of the longitudinal girder. When passing through the transverse frame (8), the transverse frame is disconnected, and the bent arc plate is continuous with the longitudinal girder. After the inner bottom plate, the inner shell and the bent arc plate pass through the transverse frame, they continue to extend forward by a length A, where 15mm < A < 100mm.

[0032] The large bracket 6 and the inner bottom plate are transitioned from butt welding to fillet welding, the longitudinal girder 7 and the lower inclined plate are fillet welded, the longitudinal girder and the transition plate are fillet welded, and the transverse frame and the lower inclined shell are fillet welded.

[0033] The inner shell 1 and the inner bottom plate 5 are bent at the position of the longitudinal girder 7 to form a bent arc plate 2 of the pressed plate. The radius of the bent arc plate is R1, where 100mm < R1 < 400mm, which is a fixed constant. The connecting plate 3 is bent and transitioned at the position of the longitudinal girder 7 to form a transition arc plate 4. The radius of the transition arc plate is R2, where 0 < R2 < R1, and it gradually decreases with the length. The bent arc plate 2 of the pressed plate is continuous with the inner bottom plate 5 and the inner shell 1, and the transverse frame 8 is discontinuous. After the longitudinal member passes through the transverse frame, it extends forward by a distance A to form a plate seam 9, where 15mm < A < 100mm. In order to release the pressure here sufficiently, the transition arc plate extends forward by a distance B, where 800mm < B < 1500mm.

[0034] A connecting plate 3 is butt-welded to the large bracket 6 to form a first weld seam 10. The distance between the first weld seam and the boundary of the transition arc plate 4 is C, where 80mm < C < 150mm. Another connecting plate 3 is butt-welded to the inner bottom plate 5 to form a second weld seam 11. The distance between the second weld seam and the boundary of the transition arc plate 4 is C, where 80mm < C < 150mm. The large bracket 6 forms a fillet weld 12 with the inner bottom plate 5 in the B area towards the bow direction.

[0035] In order to meet the welding requirements, the boundary of the inner shell plate extends outward by a distance E, which is usually taken as 50mm. In order to ensure the strength of the end of the transition arc plate, the inner shell plate extends outward and is chamfered at the end of the transition arc plate, with a distance of D, where 10mm < D < 20mm.

[0036] In this invention, the radius of the transition plate arc plate 4 at the tail end is the same as that of the bending plate arc plate 2. The radius of the transition arc plate gradually decreases, and the R2 value at the beginning becomes 0. The transition is a fillet weld, and the welds between the longitudinal girder 7 and the inner shell 1, the connecting plate 3, and the inner bottom plate 5 are continuous.

[0037] This invention effectively transitions the continuous bulkhead structure from a curved arc form to a fillet weld form through a variable arc radius transition, ensuring the tightness and continuity of key nodes in the continuous bulkhead structure. The design scheme of transitioning from a curved arc to a straight edge avoids the inability to align in confined spaces, and features convenient construction, structural continuity, material saving, high reliability, and a rational structural design, effectively reducing the number of structural components and structural weight.

Claims

1. A method for transitioning from bending an arc to welding a straight corner, characterized in that, The hull bottom plate (5) and the inner shell (1) are connected at the longitudinal girder (7) by a bent arc plate (2). The bent arc plate is a rectangular plate, and after being bent and recessed at the center, it is welded to the inner bottom plate and the inner shell respectively. The radius of the bent arc plate is R1, 100mm. <R1<400mm; The bent arc plate extends forward along the longitudinal girder. When it passes the transverse frame (8), the transverse frame breaks, and the bent arc plate becomes continuous with the longitudinal girder. After passing the transverse frame, the inner bottom plate, inner shell, and bent arc plate continue to extend forward for a length A, 15mm. <A<100mm; After the inner shell extends by length A, it forms a seam with the large elbow plate. After the bent arc plate extends by length A, it forms a seam with the transition arc plate. After the inner bottom plate extends by length A, it forms a seam with the inner bottom plate. The transition arc plate is an isosceles triangular plate. After the center of the plate is bent and recessed, it is connected to the large elbow plate and the inner bottom plate respectively through connecting plates. The radius of the transition arc plate is R2. The width of the connecting plate is C. One side of the transition arc plate is welded to the large elbow plate through a connecting plate, and the other side is welded to the inner bottom plate through another connecting plate. The bottom edge of the transition arc plate and the bending arc plate are joined to form a plate seam, and the width of the bottom edge of the transition arc plate is the same as the width of the bending arc plate. The initial value of R2 is the same as that of R1. The length of the transition arc plate is B. The large elbow plate forms a fillet weld (12) with the inner bottom plate from the end of the transition arc plate toward the bow. In the area of ​​the fillet weld, the inner floor extends outward by a length E.

2. The method for transitioning from a bent arc to a straight corner weld according to claim 1, characterized in that, The large elbow plate and the connecting plate form the first weld (10), and the inner bottom plate and the transition plate form the second weld (11). The distance between the first weld and the edge of the transition arc plate is C, and the distance between the second weld and the edge of the transition arc plate is C.

3. A method for transitioning from a bent arc to a straight corner weld according to claim 1 or 2, characterized in that, 80mm <C<150mm。 4. The method for transitioning from a bent arc to a straight corner weld according to claim 1, characterized in that, The inner shell and large elbow plate are inclined at 45° relative to the inner bottom plate.

5. The method for transitioning from a bent arc to a straight corner weld according to claim 1, characterized in that, 80mm <B<150mm。 6. The method for transitioning from a bent arc to a straight corner weld according to claim 1, characterized in that, After the transition plate is welded to the large elbow plate and the inner bottom plate, an arc-shaped weld is used at the end of the transition plate to connect the first weld and the second weld, forming a continuous weld.

7. The method for transitioning from a bent arc to a straight corner weld according to claim 1, characterized in that, The length E is 50mm.

Images