General parametric design of a steel-glubam hybrid space truss

Ma, K., and Xiao, Y. “General Parametric Design of a Steel-Glubam Hybrid Space Truss.” In Modern Engineered Bamboo Structures: Proceedings of the Third International Conference on Modern Bamboo Structures (ICBS 2018), June 25-27, 2018, Beijing, China, 1st ed., 223–29. CRC Press, 2019.

K. Ma

Zhejiang Univ.-Univ. of Illinois at Urbana Champaign Institute, Jiaxing, Zhejiang, China

Y. Xiao

Zhejiang Univ.-Univ. of Illinois at Urbana Champaign Institute, Jiaxing, Zhejiang, China

Nanjing Tech University, Nanjing, Jiangsu, China

Department of Civil Engineering, University of Southern California, Los Angeles, CA, USA

ABSTRACT: This paper introduces a parametric design method for a hybrid truss system composed of glued laminated bamboo (glubam) and steel. Experiments on determining material’s physical and mechanical parameters were carried out first, on basis of which design stages from modeling, analysis, optimization to manufacturing are all rendered possible through parametric ways by defining corresponding parameters within one single platform - Grasshopper. By maximizing automation during the process, efficiency and extensibility are taken into consideration for possibly further, larger, and more complex design.

Project: Large Waste Transfer Station

20190628 Large Waste Transfer Station 20190628 Large Waste Transfer Station

20190811 Large Waste Transfer Station 20200811 Large Waste Transfer Station

20190815 Large Waste Transfer Station 20200815 Large Waste Transfer Station

Credits

Directed by Prof. Yan Xiao.

Designed by Mark Ma.

Non-commercial project for research and demo purpose.

Project: Concrete Dragon

About the project

Concrete is something not often linked to boat, let alone dragon boat. Traditional concept of concrete based building material is embedded deeply not only in common folks but also in Civil Engineering students.

Concrete, usually Portland cement concrete (for its visual resemblance to Portland stone), is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens over time

Concrete - Wikipedia

Still, concrete is just a material, and material evolves as scientific progress advances. New material such as FRP rebars show even better performance than traditional steel rebars. Moreover, as its Chinese name indicated, concrete is just 'some sort of ash mixed and hardens', expanding its concept to a even higher dimension. Comparing to traditional boat building material, concrete has its own pros and cons.

Pros:

  • Stain proof (v.s. steel)
  • Flexible shape (v.s. timber)
  • Economical (v.s. steel and timber)

Cons:

  • Heavier than water and timber
  • Brittle
  • Low tensile strength

The whole project is aimed at exploiting the advantages of concrete while fixing its problems, expanding our knowledge of concrete through engineering practice.

Prototype 1.x - The First FRP Concrete Dragon Boat

Goal

A new type of boat construction method is proposed firstly by Prof. Yan Xiao. The basic idea is to use a self-hardening FRP cloth material as both concrete model and structural part that provides tensile strength.

20190615 Prototype 1.x Cross Section
20190615 Prototype 1.x Cross Section

Material

FRP Clothes

This is some material recently become popular for its ability of free shaping and fast hardening. Most common scenario of usage is replacement of medical bondage and plaster, or electrical wire joint protection. The mechanism is really simple as it's just piece of FRP soaked into glue. Exposition to air solidify the glue in several minutes, providing the structure with some strength.

Things become interesting when several layers of such kind of material are glued together. As FRP clothes is extremely strong in tensile direction, even glue can sustain the relatively less strong shearing force, guaranteeing high bending and shearing strength.

Plastic Hull

A plastic hull is needed for this model, primarily for the shape control of the self-hardening FRP clothes. To achieve better dynamic performance, hull is modeled to be smooth and continuous - NURBS interposition of key points. Therefore, 3D-printing technology is adopted for precise realization of the model.

20190406 3D Printing
20190406 3D Printing
20190223 Modal Boat Hull
20190223 Modal Boat Hull
20190317 Modal Boat Covered by FRP with Kaihang Zhang
20190317 Modal Boat Covered by FRP with Kaihang Zhang

Concrete

ECC concrete is a new kind of concrete which includes PVA fiber to increase its tensile strength and crack resistance. Ingredients are listed as below:

Cement1
Quartz Sand 20-401.1
Silica Fume0.3
Flyash0.15
Mineral Powder0.1
Quartz Sand 3250.1
PVA Fiber
Water0.18
Water Reduce Agents0.10%
Early Strength Agents0.10%

Next Stage

Prototype 1.x focuses itself on boat construction. A boat floating on the water marked success of the first stage. On that occasion, however, path splits for two different prototypes though.

Prototype 2.x stays small and is optimized for wireless remote control. A concrete dragon boat (model) competition is later held based on this. Prototype 3.x is develped with optimization for man-powered sailing in a much larger scale - a real concrete dragon boat.

Prototype 2.x - ICDBC 2019

Goal

Fast, stable, swift steering

To make it fast, the boat has to be speed boat alike, narrow, and light. The concrete layer needs to be as thin as possible. For sure, boat surface still needs to be smooth and continuous.

To make it stable and swift steering, the boat has to be not that narrow in width, motors parallel to each other and as far away as each other as possible.

Power system

Duo RH-380 motors, 1500mAh Li-ion battery

Should gave adopted stronger motors.

Competition

Server

https://www.concretedragon.org/

CentOS7, php7.2, MySQL5.3, Nginx, WordPress Vultr Dallas

See Concrete Dragon Online.

Rule

Should have set limitations on motor power.

Template

Should have provided ai version.

Should have made it clear that theme color can be switched.

Should have designed certificate templates.

Next stage

Should have adopted Arduino.

20190606 ICDBC Boat of My Team
20190606 ICDBC Boat of My Team
20190606 ICDBC Jury Committee with Boats
20190606 ICDBC Jury Committee with Boats
20190606 ICDBC Prof. Yan Xiao
20190606 ICDBC Prof. Yan Xiao
20190606 ICDBC Everyone
20190606 ICDBC Everyone

Prototype 3.x - The Great Dragon Boat

Goal

Strong, stable, light

The large boat is very different from the small boat as construction method can not be inherited directly. It is too slow for the hull to be 3d-printed out. Instead, EPS foam slices cut by CO2 laser are glued (or tied) up to form the basic model of the boat. A FRP clothes layer is then put on the foam, then concrete with FRP bars inside.

20190526 Laser Cut Plastic Foam
20190526 Laser Cut Plastic Foam

To make the boat strong, the boat is modeled even more smooth, to the extent that FRP rebars can be put inside the concrete from head to tail without cut or connect. Such smooth shape without any edge can be regarded as a 2-d arch, making the most of the compressive strength of the concrete. To make the boat stable, the boat should have a lower gravity center.

20190615 Prototype 2.x Cross Section
20190615 Prototype 2.x Cross Section
20190531 Great Dragon Boat Foam and Dr. Dade Lai
20190531 Great Dragon Boat Foam and Dr. Dade Lai
20190601 Great Dragon Boat Covered by Concrete
20190601 Great Dragon Boat Covered by Concrete
20190604 Great Dragon Boat under Painting
20190604 Great Dragon Boat under Painting
20190606 Great Dragon Boat
20190606 Great Dragon Boat

Next stage

  • Should have the whole boat hull made by solid EPS form.
  • Should have adopted sprayed concrete technique.
  • Should have used more PVA.
  • Should have used more FRP fiber clothes.

Credit

Instructor

Yan Xiao 肖岩

Boat Designer, Engineer, Manufacturer, Website Programmer and Designer

Ke Ma 马克

Construction

Ke Ma 马克, Dade Lai 赖大德, Zhiwei He 贺智伟

Also thanks for help by

Anqi Tan 谭安琪, Yiqi Feng 冯亦奇, Kaihang Zhang 张开航, Zhekai Li 李哲楷, Mengjun Wang 王梦君, Guoli Wang 汪郭立, Yang Zhou 周洋, Shangchun Jiang 江上春, Cristoforo Demartino, Zicheng Bao 包梓成

Decoration by

Jiahui Liang 梁嘉惠, Ke Ma 马克, Sicheng Zhou 周思成, Anqi Tan 谭安琪, Qingyun Liu 柳青云

Concrete Recipe

Bo Shan 单波, Dade Lai 赖大德

Logistic Support by

Sicheng Zhou 周思成

Competition Rule Maker

Yan Xiao 肖岩, Ke Ma 马克, Yiqi Feng 冯亦奇, Anqi Tan 谭安琪, Kaihang Zhang 张开航

Activity Organizer

Hang Wu 吴行, Ke Ma 马克, Binbin Li 李宾宾, Yanlong Xie 谢焱龙, Sichen Zhou 周思成, Tao Li 李涛, Jiahui Liang 梁嘉惠, Zhiwei He 贺智伟, Dade Lai 赖大德, Haixiang Zhu 朱海翔, Yi Zhang 张旖, Chenchen Ye 叶晨晨, Qian Yu 余倩, Jinyan Yu 俞静琰, Fengqing Jiang 江凤清 and other volunteers from ZJUI

Special Thanks for

Logistic Support

Jiyao Guo 郭霁瑶, Zhaijin Jia 贾翟菁, Qingbing Xie 谢庆兵

Technical Support

Tianyi Han 韩天屹, Si Li 李斯

Participation

Yue Feng 冯越, Hanyin Shao 邵寒吟

Sponsor

秦山建设,浙江大学创新创业学院

Project: Waste Transfer Station

20190324 Waste Transfer Station 1.0.1 Day 1 20190324 Waste Transfer Station, by Y. Xiao, K. Ma

202001030925 Waste Transfer Station 202001030925 Waste Transfer Station, Photo by S.C. Zhou

Credits

Directed by Prof. Yan Xiao.

Designed by Mark Ma.

Non-commercial project for research and demo purpose.

Project: RE Frame

Non-commercial project for research and demo purpose.

Project Introduction

This project is based on the 1st-prize-winning project 'RE Frame' of the Bamboo Pavilion Competition in Mediterranean University of Reggio Calabria by Stefano Vitale and his team. It's an honor to join him in such a great project. All following are based on my own understanding of the project.

基于Grasshopper的曲面木结构网壳参数化设计研究

马克. 基于Grasshopper的曲面木结构网壳参数化设计研究[D]:[学士学位论文].南京工业大学土木工程学院, 2018.

指导老师:陆伟东

国家重点研发项目(2017YFC0703506)资助

摘要

曲面木结构网壳具有节能、绿色、环保、经济的特点。考虑到曲面网壳形态上的不规则性,其设计、分析、优化通常较一般结构更为复杂。相比传统的设计方法,使用参数化设计方法可以大大提高其设计流程的效率,使得曲面木网壳优良的性能得以充分发挥。

目前,曲面木网壳在国外的应用较为广泛,尤其是大跨的后张拉成型网壳。国内学者在参数化网壳方面也有一定研究,但多基于规则形态的钢网壳,而在曲面木结构网壳方面的参数化研究则开展很少。

本课题基于Rhino平台Grasshopper参数化插件进行曲面木结构网壳的参数化设计研究。通过总结设计方法,归纳设计思路,进而编制参数化建模、分析、优化以及输出的相关程序,使参数化设计的效率优势在木网壳结构中得到尽可能大的发挥,以期最终形成曲面木结构网壳的参数化建模、受力分析、建造等相关问题的一体化通用解决方案,为工程实践提供借鉴和参考。

在参数化建模的具体实现上,对于传统的基于几何外观设计的规则几何形态网壳,本文逐一给出了参数化建立相关模型库的方法和示例;对于自由曲面网壳,本文给出了一种参数化网格划分及优化的思路和示例;对于后张拉成型网壳,本文给出了通过模拟倒悬法动态优化建立模型的思路和示例。

在参数化受力分析、优化的实现上,本文基于Grasshopper插件给出了一种有限元分析方法并验证了其可靠性。该方法不仅能参数化分析传统网壳的受力,也能为模拟倒悬法找形获得的后张拉成型网壳提供精确的找形计算。在此基础上给出了此外,给出了基于进化算法对曲面整体做几何优化的思路和示例。

关键词:木网壳 参数化设计 Grasshopper


Voronoi 4.2
Voronoi 4.2

致谢

感谢陆伟东教授、孙小鸾老师、屈丽荣博士、陆斌辉学长为本课题提供的指导,正是他们给出的指导和建议使本课题的开展成为可能。尤其感谢我的导师陆伟东教授,他敏锐的学术洞察力使我在课题中受益良多;也要感谢屈丽荣博士,她同样在整个课题期间倾注了大量心血和精力,提出了许多宝贵的指导和建议。

感谢Grasshopper的开发者David Rutten以及整个社区,特别是Paneling Tools, Kangaroo(2), LunchBox, NGon, Karamba等插件和他们的开发者。他们的工作为本课题的开展提供了巨大的便利,并在实际应用中带给了我一些思路上的启发。

感谢工E设计,使我在大学期间得以学习到几乎一切用于此论文的展示工具,并指导了我在艺术设计领域上的发展,尤其感谢赵文炀、韦雨杏在建筑学上的指导。

感谢一路关心、理解、支持我的父母,老师,朋友。无论课题进展是喜是忧,总能得到你们的鼓励和帮助。正是你们在过去的二十多年中的不断影响使我走到了现在,我的感恩之情无以言表。

一个人的历史造就了他的如今,而整个人类的历史亦是他的后盾。在学术研究的道路上,无数先人开辟道路,才有了如今我这些微小的工作。感谢所有。


参见

[1] 关于公布南京工业大学2018届本科生优秀毕业设计(论文)、优秀指导教师的通知

Credits

Designed by Mark Ma.

Non-commercial project for research and demo purpose.

Produced with

  • Rhino 6, Educantional License
  • Lumion 6, Trial License
  • Adobe Creative Cloud, Educational License