Calculation method of still water shear force and bending moment based on STL model
Article Text (Baidu Translation)
-
摘要: 为了提高船舶强度计算精度, 提出了一种基于STL模型的船舶静水剪力与弯矩计算方法。在计算总纵强度时, 采用常规算法计算船舶浮态初值, 然后采用迭代算法计算船舶吃水、横倾角与吃水差; 按照船舶肋位切割船舶外壳得到每个肋位的横剖面, 采用格林公式计算每个剖面水下部分的面积, 纵向积分得到浮力曲线; 通过对船舶舱室STL模型的切割, 离线建立每个舱室的质量分布表, 用舱室实际质量分布代替梯形分布来计算船舶质量分布曲线; 最后基于散货船“太行128”和“SPRING COSMOS”, 通过浮力与质量分布曲线计算了5种典型载况下的剪力与弯矩。计算结果表明: 计算值与采用软件NAPA的设计值相比, 剪力与弯矩的平均误差约为1%, 最大误差为2.6%, 计算误差较小, 因此, 船舶静水剪力与弯矩计算方法精度较高; 采用浮态迭代算法只需计算出船舶任意浮态下的排水体积与浮心坐标, 程序实现简单、稳定与可靠; 静水剪力与弯矩计算方法适用于船舶任意浮态, 通过直接切割船舶外壳计算船舶浮力曲线, 弥补了常规方法只能计算船舶纵向强度的不足; 通过建立舱室的质量分布表与采用舱室的实际质量分布代替传统的梯形分布, 减少了计算量, 提高了计算精度。Abstract: To improve the calculation accuracy of ship strength, a method based on STL model was proposed to calculate still-water shear force and bending moment of ship.In calculating the total longitudinal strengths, the initial values of ship floating condition were calculated by the conventional method, and then the draught, heeling angle and trim of ship were calculated by the iteration method.The transverse section of each rib was obtained by cutting the hull according to the rib position, the area of underwater part of each section was calculated by using the Green formula, and the buoyancy curve was obtained by the longitudinal integration.The mass distribution table of each cabin was established offline by cutting the STL model of ship cabin, and the actual mass distribution of cabin was used instead of the trapezoid mass distribution to calculate the mass distribution curve.Finally, based on the distribution curves of buoyancy and mass, the bulk carriers "Taihang 128"and "SPRING COSMOS"were taken as examples tocalculate the shear forces and bending moments under 5 typical loading conditions.Calculation result shows that the average relative errors of shear forces and bending moments calculated by the proposed method and the design software NAPA of ship are about 1%, the maximum error is 2.6%, the errors are smaller, so the accuracy of proposed method is higher.The iterative algorithm of ship floating condition only needs to calculate the drainage volume and buoyancy center coordinates of ship in free floating condition, so the program is simple, stable and reliable.The proposed method is applied to any floating condition of ship, the buoyancy distribution curve of ship can be calculated by directly cutting the hull, so the proposed method makes up for the deficiency of the conventional method that can calculate only ship's longitudinal strength.By establishing the mass distribution table of ship cabins and using the actual distribution of mass instead of the traditional trapezoid distribution of mass, the calculation precision of ship strength rises, and the calculated amount reduces.
-
Key words:
- ship engineering /
- still-water shear force /
- bending moment /
- STL model /
- free floatation /
- loading computer
-
图 14 压载出港剪力与弯矩相对误差
Figure 14. Relative error of shear forces and bending moments under ballasting departure
图 15 满载到港剪力与弯矩相对误差
Figure 15. Relative errors of shear forces and bending moments under fully loaded arrival
图 17 许用剪力与弯矩相对误差
Figure 17. Relative errors of allowable shear forces and bending moments
-
[1] PAIK J K, MANSOUR A E. A simple formulation for predicting the ultimate strength of ships[J]. Journal of Marine Science and Technology, 1995, 1 (1): 52-62. doi: 10.1007/BF01240013 [2] GORDO J M, SOARES C G, FAULKNER D. Approximate assessment of the ultimate longitudinal strength of the hull girder[J]. Journal of Ship Research, 1996, 40 (1): 60-69. doi: 10.5957/jsr.1996.40.1.60 [3] TALMON A M, BEZUIJEN A. Calculation of longitudinal bending moment and shear force for Shanghai Yangtze River Tunnel: application of lessons from Dutch research[J]. Tunnelling and Underground Space Technology, 2013, 35 (3): 161-171. [4] SHU Z, MOAN T. Ultimate hull girder strength of a bulk carrier under combined global and local loads in the hogging and alternate hold loading condition using nonlinear finite element analysis[J]. Journal of Marine Science and Technology, 2012, 17 (1): 94-113. doi: 10.1007/s00773-011-0147-9 [5] 王峰, 陈毓珍, 张青敏. 全船有限元简化方法在总纵强度计算中的应用[J]. 船舶与海洋工程, 2014 (1): 24-27. doi: 10.3969/j.issn.2095-4069.2014.01.005WANG Feng, CHEN Yu-zhen, ZHANG Qing-min. Application of a simplified finite element method of whole ship in total longitudinal strength computation[J]. Naval Architecture and Ocean Engineering, 2014 (1): 24-27. (in Chinese). doi: 10.3969/j.issn.2095-4069.2014.01.005 [6] 黄敏. 3 000DWT甲板货船总纵强度计算分析[J]. 中国水运, 2013, 13 (11): 28-29. https://www.cnki.com.cn/Article/CJFDTOTAL-ZSUX201311015.htmHUANG Min. Total longitudinal strength calculation analysis of 3 000DWT vdeck cargo[J]. China Water Transport, 2013, 13 (11): 28-29. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZSUX201311015.htm [7] 孙一方. 基于NURBS技术的散货船配载仪设计[D]. 哈尔滨: 哈尔滨工程大学, 2012.SUN Yi-fang. Design of the bulk carrier loading software based on NURBS technology[D]. Harbin: Harbin Engineering University, 2012. (in Chinese). [8] 郭雷. 驳船配载系统工程问题研究[D]. 大连: 大连理工大学, 2012.GUO Lei. Research on the system of engineering problems for barge stowage[D]. Dalian: Dalian University of Technology, 2012. (in Chinese). [9] 杨义益. 基于NAPA考虑挠度的甲板货船总纵强度校核系统研究[D]. 镇江: 江苏科技大学, 2011.YANG Yi-yi. Research on program system for the longitudinal strength of deck cargo ship considering deflection based on NAPA[D]. Zhenjiang: Jiangsu University of Science and Technology, 2011. (in Chinese). [10] 肖红文, 刘家新. 江海直达货船总纵强度规范计算与研究[J]. 船海工程, 2011, 40 (6): 35-39. doi: 10.3963/j.issn.1671-7953.2011.06.010XIAO Hong-wen, LIU Jia-xin. Calculation and analysis on longitudinal strength of rive-to-sea ship[J]. Ship and Ocean Engineering, 2011, 40 (6): 35-39. (in Chinese). doi: 10.3963/j.issn.1671-7953.2011.06.010 [11] 徐瑜. 基于沿海货船的总纵强度研究[D]. 大连: 大连海事大学, 2009.XU Yu. Research of longitudinal strength based on coastal vessel[D]. Dalian: Dalian Maritime University, 2009. (in Chinese). [12] 杨彩虹. 船用装载仪相关技术的研究与开发[D]. 哈尔滨: 哈尔滨工程大学, 2009.YANG Cai-hong. Research and development of loading computer for ships[D]. Harbin: Harbin Engineering University, 2009. (in Chinese). [13] 韩永波. 基于数字型值表的船舶强度校核与装载仪设计[D]. 大连: 大连海事大学, 2007.HAN Yong-bo. Strength check and stowage system design of ship based on digital table of offsets[D]. Dalian: Dalian Maritime University, 2007. (in Chinese). [14] 姜广煜, 谢云平, 刘可峰, 等. 基于NAPA大宽深比船舶总纵强度计算方法与分析[J]. 江苏科技大学学报: 自然科学版, 2007, 21: 21-23. https://www.cnki.com.cn/Article/CJFDTOTAL-HDCB2007S1007.htmJIANG Guang-yu, XIE Yun-ping, LIU Ke-feng, et al. Calculation and analysis of longitudinal strength of great breadth depth ratio ship based on NAPA[J]. Journal of Jiangsu University of Science and Technology: Natural Science Edition, 2007, 21: 21-23. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-HDCB2007S1007.htm [15] RONG Lei, CUI Jian-hui. Comparison between vessel's displacements calculated by Bonjean curves and Hydrostatic curves[J]. Applied Mechanics and Materials, 2013, 278-280 (1): 35-39. [16] WANG Xiao-zhi, MOAN T. Stochastic and deterministic combinations of still water and wave bending moments in ships[J]. Marine Structures, 1996, 9 (8): 787-810. doi: 10.1016/0951-8339(95)00022-4 [17] HANSCH D L. Methods of determining the longitudinal weight distribution of a ship[C]//Society of Allied Weight Engineers. 67th Annual conference of International Society of Allied Weight Engineers. Seattle: Society of Allied Weight Engineers, 2008: 2-19. [18] 刘春雷, 尹勇, 孙霄峰, 等. 基于STL模型的船舶几何特性计算[J]. 系统仿真学报, 2015, 27 (10): 2264-2271. https://www.cnki.com.cn/Article/CJFDTOTAL-XTFZ201510006.htmLIU Chun-lei, YIN Yong, SUN Xiao-feng, et al. Calculation of vessel's geometric properties based on STL model[J]. Journal of System Simulation, 2015, 27 (10): 2264-2271. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-XTFZ201510006.htm [19] 段兴锋, 任鸿翔, 东昉. 纵倾状态船舶浮态的研究与计算[J]. 中国航海, 2015, 38 (1): 54-57. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGHH201501014.htmDUAN Xing-feng, REN Hong-xiang, DONG Fang. Calculation of floating condition of a longitudinal inclined ship[J]. Navigation of China, 2015, 38 (1): 54-57. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZGHH201501014.htm [20] 刘春雷, 尹勇, 孙霄峰, 等. 船舶浮态计算的一种修正方法[J]. 大连海事大学学报, 2014, 40 (4): 1-6. https://www.cnki.com.cn/Article/CJFDTOTAL-DLHS201404001.htmLIU Chun-lei, YIN Yong, SUN Xiao-feng, et al. A modified method to ship floating calculation[J]. Journal of Dalian Maritime University, 2014, 40 (4): 1-6. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-DLHS201404001.htm [21] CHEN Jing, LIN Yan, HUO Jun-zhou, et al. Optimization of ship's subdivision arrangement for offshore sequential ballast water exchange using a non-dominated sorting genetic algorithm[J]. Ocean Engineering, 2010, 37 (11/12): 978-988. [22] CHEN Jing, LIN Yan, HUO Jun-zhou, et al. Optimal ballast water exchange sequence design using symmetrical multitank strategy[J]. Journal of Marine Science And Technology, 2010, 15 (3): 280-293. doi: 10.1007/s00773-010-0087-9 [23] 赵晓非, 林焰. 关于解船舶浮态问题的矩阵方法[J]. 中国造船, 1985 (3): 57-66. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGZC198503005.htmZHAO Xiao-fei, LIN Yan. Matrix methods for solving ship floating state problem[J]. Shipbuilding of China, 1985 (3): 57-66. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-ZGZC198503005.htm [24] 林焰, 李铁骊, 纪卓尚. 破损船舶自由浮态计算[J]. 大连理工大学学报, 2001, 41 (1): 85-89. https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG200101021.htmLIN Yan, LI Tie-li, JI Zhuo-shang. Ship damage floating calculation[J]. Journal of Dalian University of Technology, 2001, 41 (1): 85-89. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG200101021.htm [25] 马坤, 张明霞, 纪卓尚. 基于非线性规划法的船舶浮态计算[J]. 大连理工大学学报, 2003, 43 (3): 329-331. https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG200303016.htmMA Kun, ZHANG Ming-xia, JI Zhuo-shang. Ship floating calculation based on nonlinear programming[J]. Journal of Dalian University of Technology, 2003, 43 (3): 329-331. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-DLLG200303016.htm [26] 孙承猛, 刘寅东. 船舶浮态计算的一种优化方法[J]. 大连海事大学学报, 2006, 32 (2): 39-41. https://www.cnki.com.cn/Article/CJFDTOTAL-DLHS200602010.htmSUN Cheng-meng, LIU Yan-dong. Optimization method for ship's floating condition calculation[J]. Journal of Dalian Maritime University, 2006, 32 (2): 39-41. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-DLHS200602010.htm [27] 陆丛红, 林焰, 纪卓尚. 遗传算法在船舶自由浮态计算中的应用[J]. 上海交通大学学报, 2005, 39 (5): 701-705. https://www.cnki.com.cn/Article/CJFDTOTAL-SHJT200505009.htmLU Cong-hong, LIN Yan, JI Zhuo-shang. Application of genetic algorithm in ship free floatation calculation[J]. Journal of Shanghai Jiaotong University, 2005, 39 (5): 701-705. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-SHJT200505009.htm [28] LU Cong-hong, LIN Yan, JI Zhuo-shang. Free trim calculation using genetic algorithm based on NURBS shipform[J]. International Shipbuilding Progress, 2007, 54 (1): 45-62. [29] CALABRESE F, MANCARELLA L, ZIZZARI A A, et al. A multidisciplinary method for evaluating ship stability[J]. Journal of Shipping and Ocean Engineering, 2012 (6): 321-326. [30] AZCUETA R. Computation of turbulent free-surface flows around ships and floating bodies[J]. Ship Technology Research, 2002, 49: 999-1022. -
下载:
点击查看大图
图(18) / 表(4)
计量
- 文章访问数: 2284
- HTML全文浏览量: 948
- PDF下载量: 740
- 被引次数: 0
