Lightweight design of large scale theodolite's turntable based on topology optimization of continuum structure

Abstract In order to solve the application restrictions of deterministic-based topology optimization methods arising from the omission of uncertainty factors in practice, and to realize the calculation cost control of reliability-based topology optimization. In consideration of the current reliability-based topology optimization methods of continuum structures mainly based on performance indexes model with a power filter function. An efficient probabilistic reliability-based topology optimization model that regards mass and displacement as an objective function and constraint is established based on the first-order reliability method and a modified economic indexes model with a composite exponential filter function in this study. The topology optimization results obtained by different models are discussed in relation to optimal structure and convergence efficiency. Through numerical examples, it can be seen that the optimal layouts obtained by reliability-based models have an increased amount of material and more support structures, which reveals the necessity of considering uncertainty in lightweight design. In addition, the reliability-based modified model not only can obtain lighter optimal structures compared with traditional economic indexes models in most circumstances, but also has a significant advantage in convergence efficiency, with an average increase of 44.59% and 64.76% compared with the other two reliability-based models. Furthermore, the impact of the reliability index on the results is explored, which verifies the validity of the established model. This study provides a theoretical reference for lightweight or innovative feature-integrated design in engineering applications.

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Structural topology optimization of bridge girders in cable supported bridges

IABSE Conference, Kuala Lumpur 2018: Engineering the Developing World ◽

10.2749/kualalumpur.2018.0975 ◽

2018 ◽

Author(s):

Mads Baandrup ◽

Ole Sigmund ◽

Niels Aage

Keyword(s):

Topology Optimization ◽

Large Scale ◽

Design Method ◽

Optimization Method ◽

Bridge Girders ◽

Structural Topology ◽

Box Girders ◽

Box Girder ◽

Fine Mesh ◽

Further Development

This work applies a ultra large scale topology optimization method to study the optimal structure of bridge girders in cable supported bridges.The current classic orthotropic box girder designs are limited in further development and optimiza tion, and suffer from substantial fatigue issues. A great disadvantage of the orthotropic girder is the loads being carried one direction at a time, thus creating stress hot spots and fatigue problems. Hence, a new design concept has the potential to solve many of the limitations in the current state of-the-art.We present a design method based on ultra large scale topology optimization. The highly detailed structures and fine mesh-discretization permitted by ultra large scale topology optimization reveal new design features and previously unseen eff ects. The results demonstrate the potential of gener ating completely different design solutions for bridge girders in cable supported bridges, which dif fer significantly from the classic orthotropic box girders.The overall goal of the presented work is to identify new and innovative, but at the same time con structible and economically reasonable, solutions tobe implemented into the design of future cable supported bridges.

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Enhanced Comprehension of the Continuous Fusion Bonding Process of Multi-Material Structures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.939.197 ◽

2018 ◽

Vol 939 ◽

pp. 197-204 ◽

Cited By ~ 2

Author(s):

Tobias Reincke ◽

Sven Hartwig ◽

Klaus Dilger

Keyword(s):

Composite Structures ◽

Large Scale ◽

Lightweight Design ◽

Continuous Process ◽

Peel Test ◽

Roll Forming ◽

Scale Production ◽

Continuous Manufacturing ◽

Fusion Bonding ◽

Reinforced Thermoplastics

In comparison to monolithic composite structures, tailored multi-material structures offer high potential considering lightweight design approaches in combination with cost efficient manufacturing processes. Roll forming enables flexible large scale production of hybrid structures, due to the continuous manufacturing process as well as high degree of automation. The multi-material structures consist of steel sheets which are selectively reinforced by unidirectional carbon fibre reinforced thermoplastics (CFR-TP). In view of minimizing process steps and decreasing cycle times, both materials are joined by fusion bonding. Therefore, CFR-TP is heated above melting temperature of thermoplastic matrix and joined to the steel surface under defined pressure and time. However, joining of both materials within a continuous process is still challenging due to a lack in terms of process comprehension. Consequently, multi-material specimens were manufactured depending on various process parameters as temperature of either material or processing speed and tested mechanically by floating roller peel test for the evaluation of the adhesion between both materials. Furthermore, viscosity of matrix was determined and investigations of CFR-TP interface were performed by Fourier transform infrared spectroscopy. The results show the requirement of a defined CFR-TP temperature and the change in crystalline structure of the matrix in dependency of the processing.

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Lightweight Design of Shipbuilding Gantry Crane Structure Based on FEA

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.474-476.131 ◽

2011 ◽

Vol 474-476 ◽

pp. 131-136 ◽

Cited By ~ 1

Author(s):

Ming Liang Yang ◽

Ge Ning Xu ◽

Zheng Yan Chang

Keyword(s):

Strain Distribution ◽

Large Scale ◽

Lightweight Design ◽

Metal Structure ◽

Structure Design ◽

Gantry Crane ◽

Stress And Strain ◽

Analytical Computation ◽

Structural Improvement ◽

Stress And Strain Distribution

For the sake of working safely and stable, large-scale shipbuilding gantry crane was designed based on the principle of metal structure:3S,Strength,Stiffness,Stability. The detailed finite element analytical computation was successfully carried out on this structure, the stress and strain distribution of this structure were obtained under various actual operations. On the basis of it, the structural improvement was carried out, the result of design indicated that the stress was evident and the weight was lightened. This laid a foundation for the structure design of large-scale shipbuilding gantry crane.

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Strategy and numerical modelling of a vehicle seat with a lightweight sandwich design for large-scale production

Technologies for Lightweight Structures (TLS) ◽

10.21935/tls.v1i2.96 ◽

2018 ◽

Vol 1 (2) ◽

Author(s):

Song Ren ◽

Kay Schäfer ◽

Daisy Nestler ◽

Dominik Krumm ◽

Stephan Odenwald ◽

...

Keyword(s):

Large Scale ◽

Static Load ◽

Lightweight Design ◽

Scale Production ◽

Front Seat ◽

Element Analysis ◽

Large Scale Production ◽

Spacer Fabric ◽

Glass Fibre Reinforced ◽

Vehicle Seat

A lightweight vehicle front seat with a sandwich structure, which consists of skin layers made of glass fibre-reinforced thermoplastic prepregs and a core consisting of a warp knitted spacer fabric filled with polyurethane foam, was developed. The strength test simulations of the seat structure were performed using a Finite Element Analysis approach. The results validate the new sandwich design of the vehicle seat with its adequate strength under a static load. With the innovative lightweight design, the mass of the seat was reduced up to 57 % in comparison to the reference seat from conventional mass production. In addition, a manufacturing process was advised for a large-scale production of the lightweight design within one workstation.

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