Inner shell bevel line setting method

Abstract

An inner shell bevel line setting method includes the steps that firstly, an initial frame of a ship is formed, a lower break point and an upper break point of the frame are shifted downwards and upwards by 2 meters respectively to form limiting line points, a limiting molded line is formed through the limiting line points, the inner shell bevel line form of the whole ship is coordinated according to the molded line, and the safety, economy and environment friendliness of the whole ship are improved. By optimizing the geometrical shape, strengthening the structural strength and adopting an advanced manufacturing process, the comprehensive performance of the ship can be remarkably improved, and long-term reliable operation of the ship under complex sea conditions is ensured. The construction process is simplified, the strength requirement is met, the structural weight is reduced, and the overall loading capacity of the ship is increased.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of shipbuilding and design, and particularly relates to a method for setting an inner shell corner line. BACKGROUND

[0002] The inner shell corner line is a key element in the structural design of a double-hulled oil tanker, directly affecting the safety, structural strength, construction process and operational efficiency of the ship.

[0003] The inner shell corner line is the transition area between the longitudinal bulkhead and the bottom or top edge tank, and bears the task of transmitting longitudinal and transverse loads. During ship navigation, the hull is subjected to various loads such as wave impact, cargo pressure and mechanical vibration, and reasonable design of the corner line can effectively disperse stress and avoid local stress concentration leading to steel plate cracking or deformation. If the corner line is not designed properly, it may lead to structural fatigue and even cause catastrophic accidents.

[0004] The geometry of the corner line directly affects the available space of the cargo tank. Reasonable design of the corner line (such as using a circular arc transition or a beveled corner) can maximize the cargo tank volume and increase the cargo capacity. At the same time, a smooth corner line helps to reduce cargo residue, facilitating cleaning and maintenance, and meeting the MARPOL Convention requirements for oil tanker cargo tank cleanliness.

[0005] Due to the complex stress variation in the corner line area, which bears alternating loads for a long time, its design directly affects the fatigue life of the ship. The design of the corner line needs to take into account the construction process, such as the feasibility of cold bending or hot bending forming. Reasonable corner line shape can reduce processing difficulty and improve construction efficiency. At the same time, the corner line area is usually provided with a maintenance access (width ≥ 600 mm) for daily inspection and maintenance, meeting the inspection requirements of classification societies (such as DNV, ABS).

[0006] The inner shell corner line must meet international standards such as IMO MARPOL Convention and IACS CSR (Common Structural Rules) to ensure the environmental compliance of the ship. For example, the position of the corner line of a double-hulled oil tanker must meet the minimum double-hull spacing requirement (such as ≥ 2 m) to prevent oil tank leakage from polluting the marine environment.

[0007] Therefore, the design of the corner line is a key link that cannot be ignored in ship engineering. Currently, there is no method for setting the inner shell corner line. SUMMARY

[0008] To solve the above problems, the present application provides a method for setting an inner shell corner line, aiming to reasonably set the corner line to maximize the tank capacity, and the technical solution adopted is: A method for setting an inner shell corner line, the specific setting steps are as follows: S1: Draw the initial frame of the ship according to the design requirements of the ship, determine the double bottom height as L1 and the double shell width as L2 according to the total amount of ballast water, and form the inner bottom limiting line point M1 by offsetting the following fold point downward by 2m and forming the inner shell limiting line point M2 by offsetting the upper fold point outward by 2m.

[0009] S2, introduce all the lines of the parallel mid-body region of the ship into the initial frame according to the rib position number one by one, and the ship lines become thinner and thinner from the middle to both ends, stop when the lines introduced to the bow and the lines introduced to the stern intersect with the limiting line points M1 or M2, define the lines intersecting with the limiting line M1 as FRs, and define the lines intersecting with the limiting line M2 as FRw.

[0010] S3, introduce the lines of FRs to the bow into the initial frame according to the rib position number one by one, at this time the inner shell inclined plate will shrink inward at an angle R according to the lines, offset the FRsn line inward by 2000mm, the offset line FRsn' intersects with the inner bottom of the ship to form intersection point Psn1, the offset line FRsn' intersects with the inner shell to form intersection point Psn2, intersection point Psn1 and intersection point Psn2 form a new inner shell inclined plate 2frn, when the intersection point Psn2 is determined as the minimum point of the lines and the new inner shell inclined plate, a perpendicular line is drawn upward through Psn2 to form a new inner shell 4frn.

[0011] When the lines shrink inward and the intersection point Psn2 is not the minimum point, a vertical line is drawn downward from the minimum point Psn3 to intersect with the inner shell inclined plate to form a new inner shell fold angle line.

[0012] Wherein, FRsn is the line of the rib position number n of FRs to the bow.

[0013] S4, after gradually completing all the lines of the cargo hold area to the bow, the process is ended.

[0014] S5, introduce the lines of FRw to the stern into the initial frame according to the rib position number one by one, at this time the lower inclined plate will shrink inward at an angle R according to the lines, offset the FRwn rib position line inward by 2000mm to form the offset line FRwn', the offset line FRwn' intersects with the inner bottom of the ship to form intersection point Pwn1, the offset line FRwn' intersects with the inner shell of the ship to form intersection point Pwn2, the line connecting Pwn1 and Pwn2 forms a new inner shell inclined plate, when the intersection point is determined as the minimum point of the lines and the lower inclined plate, a perpendicular line is drawn upward through Pwn2 to form a new inner shell 4frn.

[0015] When the lines shrink inward and the intersection point Pwn2 is not the minimum point, a vertical line is drawn downward from the minimum point Pwn3 to intersect with the inner shell inclined plate to form a new inner shell fold angle line.

[0016] Wherein, FRwn is the line of the rib position number n of FRw to the stern.

[0017] S6, in order to be able to increase the cargo hold, when the stern gradually flat, with Pwn1 tilt up and the inner shell Pwn2, Pwn1 and Pwn2 form a straight line with the type line offset line FRwn' distance is far, at this time can be with the intersection of the inner shell and the type line offset line Pwn2' downward tilt line, shorten the offset line and the new inner shell line spacing, with the inner shell forming intersection Pwn4, at this time Pwn4 and the outer plate distance is less than 2m, in the case of meeting the specification, the maximum capacity.

[0018] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0019] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0020] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0021] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0022] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0023] The above-mentioned inner shell corner line setting method is further provided with a box at the intersection of the inner shell inclined plate and the inner bottom, the box height is M3, the width is M4, and the width M4 is determined after the intersection of the parallel line and the inclined inner shell.

[0024] The present application can coordinate the inner shell corner line form of the whole ship according to the type line, improve the safety, economy and environmental protection of the whole ship. By optimizing the geometric shape, strengthening the structural strength and adopting advanced manufacturing process, the comprehensive performance of the ship can be significantly improved, and the long-term reliable operation of the ship in complex sea conditions can be ensured. Simplify the construction process, meet the strength requirements, reduce the structure weight, and increase the overall loading capacity of the ship. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic view of the inner shell corner line in the parallel mid-body region of the cargo hold area; Figure 2 is a schematic view of the inner shell corner line in the bow cargo hold area; Figure 3 is a schematic view of the inner shell corner line in the bow cargo hold area; Figure 4 is a schematic view of the inner shell corner line in the bow cargo hold area; Figure 5 Schematic diagram of the inner hull bend line of the stern cargo hold (with small box); Wherein, 1-hull outer plating, 2-inner hull inclined plate, 3-side outer plating, 4-inner hull, 6-inner bottom plate, L1-double bottom height, L2-double hull width, M1-inner bottom limiting point, M2-inner hull limiting point, R-inner hull inclined plate angle. Detailed Implementation

[0026] The invention will be further described with reference to the accompanying drawings.

[0027] A method for setting the inner shell corner line, the specific steps of which are as follows: S1, based on ship design requirements and the total ballast water volume, determine the double bottom height as L1, the double hull width as L2, and the lower ramp inclination angle as R. Draw the initial border, as follows: Figure 1 As shown. The lower inflection point is offset downwards by 2m to form the inner bottom limiting line M1, and the upper inflection point is offset outwards by 2m to form the inner shell limiting line point M2. This is to meet the requirements of the IMO MARPOL Convention. Figure 1 As shown.

[0028] S2 imports all the hull lines in the parallel midbody region of the ship into the initial border one by one according to the rib number. The ship's hull lines become thinner from the middle to both ends. The process stops when the hull lines imported towards the bow and stern intersect with the restriction lines M1 or M2, defined as FRs and FRw. The inner hull bend lines drawn by the hull lines within the middle range of these intersecting hull lines are consistent with the initial inner hull lines. For example... Figure 2 As shown.

[0029] S3, as Figure 3 As shown, the FRs profile towards the bow is imported into the initial frame one by one according to the rib number. At this time, the lower sloping plate will shrink inward at an angle R according to the profile. The FRsn rib profile is offset inward by 2000mm. The offset line FRsn' intersects with the ship's inner bottom at point Psn1. The new inner shell sloping plate 2frn intersects with the offset line FRsn' at point Psn2. When this intersection point is determined to be the minimum point between the profile and the lower sloping plate, a vertical line is drawn vertically upward through Psn2 to form a new inner shell 4frn. When the profile shrinks inward and the intersection point Psn2 is not the minimum point, a vertical line is drawn downward from the minimum point Psn3 as the base point to intersect with the inner shell sloping plate to form a new bend line.

[0030] S4, gradually completing all the shaped lines from the cargo hold area to the bow, then ends.

[0031] S5, such as Figure 4As shown, the FRw profile to the tail of the rib position number is introduced into the initial frame one by one, at this time the lower inclined plate will be according to the profile to the angle R inward shrink. The FRwn rib position profile is offset inward 2000mm, forming the offset line FRwn', offset line FRwn' with the ship bottom forming intersection Pwn1, from Pwn1 upward with the new inner shell inclined plate 2frn and offset line FRwn' forming intersection Pwn2, determine this intersection as the minimum point of the profile and the lower inclined plate, through Pwn2 vertically upward do perpendicular, form the new inner shell 4frn. When the profile inward shrink, intersection Pwn2 is not the minimum point, with the minimum point Pwn3 as the base point do perpendicular line downward and the inner shell inclined plate intersection form a new corner line.

[0032] S6, as Figure 5 shown, in order to be able to increase the cargo hold capacity, when the tail profile gradually flat, with Pwn1 inclined upward and inner shell forming Pwn2, Pwn1 and Pwn2 form a straight line with the profile offset line distance far, at this time can be with the intersection of the inner shell and the profile offset line Pwn2' downward do inclined line shorten the distance between the offset line and the new inner shell line, with the inner shell forming intersection Pwn4, at this time Pwn4 and the outer plate distance is less than 2m. In order to meet the requirements of IMO MARPOL convention, at the same time increase the cargo hold capacity, can be set up a small box between the inner shell inclined plate and the inner bottom, high M3, width M4.1600mm

Claims

1. A method for setting the corner line of an inner shell, characterized in that, The specific setup steps are as follows: S1: Draw the initial frame of the ship according to the design requirements. Determine the double bottom height as L1 and the double hull width as L2 according to the total ballast water volume. Offset the lower inflection point downward by 2m to form the inner bottom limit line point M1, and offset the upper inflection point outward by 2m to form the inner hull limit line point M2. S2, import all the hull lines in the parallel midbody area of ​​the ship into the initial frame one by one according to the rib number. The ship's hull lines become thinner from the middle to both ends. Stop when the hull lines imported towards the bow or the hull lines imported towards the stern intersect with the restriction line point M1 or M2. Define the hull lines that intersect with the restriction line point M1 towards the bow as FRs, and define the hull lines that intersect with the restriction line point M2 towards the stern as FRw. S3, import the FRs profile towards the bow into the initial frame one by one according to the rib number. At this time, the inner shell inclined plate will shrink inward at an angle R according to the profile. The FRsn profile will be offset inward by 2000mm. The offset line FRsn' intersects with the inner bottom of the ship at point Psn1. The offset line FRsn' intersects with the inner shell at point Psn2. The intersection points Psn1 and Psn2 form a new inner shell inclined plate 2frn. When the intersection point Psn2 is determined to be the minimum point between the profile and the new inner shell inclined plate, draw a perpendicular line vertically upward through Psn2 to form a new inner shell 4frn. When the profile contracts inward and the intersection point Psn2 is not the minimum point, a vertical line is drawn downward from the minimum point Psn3 as the base point to intersect with the inclined plate of the inner shell to form a new inner shell bend line. Wherein, FRsn is the profile line with FRs numbered n towards the bow rib; S4, the process ends after gradually completing all the hull lines from the cargo hold area to the bow; S5, import the FRw profile towards the stern into the initial frame one by one according to the rib number. At this time, the lower sloping plate will shrink inward at an angle R according to the profile. The FRwn rib profile will be offset inward by 2000mm to form the offset line FRwn'. The offset line FRwn' intersects with the ship's inner bottom at point Pwn1. The offset line FRwn' intersects with the ship's inner hull at point Pwn2. The line connecting Pwn1 and Pwn2 forms a new inner hull inclined plate. When this intersection point is determined to be the minimum point between the profile and the new inner hull inclined plate, draw a vertical line upward through Pwn2 to form a new inner hull 4frn. When the profile contracts inward and the intersection point Pwn2 is not the minimum point, a vertical line is drawn downward from the minimum point Pwn3 as the base point to intersect with the inclined plate of the inner shell to form a new inner shell bend line. Among them, FRwn is the rib line with the number n in the stern direction of FRw; S6. In order to increase the cargo hold capacity, when the stern profile gradually flattens out, Pwn1 is tilted upward to form Pwn2 with the inner shell. The straight line formed by Pwn1 and Pwn2 is far from the profile offset line. At this time, the intersection point Pwn2' of the inner shell and the profile offset line can be tilted downward to shorten the distance between the offset line and the new inner shell line, forming the intersection point Pwn4 with the inner shell. At this time, the distance between Pwn4 and the outer plate is less than 2m.

2. The method for setting the inner shell corner line according to claim 1, characterized in that, A box is provided at the intersection of the inclined plate of the inner shell and the inner bottom. The height of the box is M3 and the width is M4. The width M4 is the intersection of the parallel line after M3 is determined and the inclined inner shell.

3. The method for setting the inner shell corner line according to claim 1, characterized in that, The inner shell bend line drawn by the profile between FRs and FRw is consistent with the initial inner shell line.

4. The method for setting the inner shell corner line according to claim 2, characterized in that, 1600mm <M3<3000mm。 5. The method for setting the inner shell corner line according to claim 2, characterized in that, The small box extends continuously along the length of the ship and is reinforced with internal ribs.

6. The method for setting the inner shell corner line according to claim 1, characterized in that, The height L1 of the double bottom and the width L2 of the double shell are both greater than 2 meters.

7. The method for setting the inner shell corner line according to claim 1, characterized in that, Psn3 is the constraint point for the FRsn type line to be offset inward by 2m, and it is the only constraint point that meets the 2m requirement.

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