The Consideration of Welding Profiles in Fatigue Evaluation of Structure Design

Author(s):  
D. Zhang

Structural fatigue plays a very important role in plating structural design. There are a lot of efforts in finding effective ways to improve the fatigue life of the plating structure. One of the means is to use welding profile. Welding profile is widely used in fatigue sensitive areas to improve the fatigue life of offshore platforms. How to evaluate the impact of welding profile to fatigue life calculation has always been the topic of engineering design. This paper will study the impact of different shapes of welding profiles to the fatigue life of structure through a real project example, and discuss its application in platform design. Different welding profiles have large impact on fatigue life; and an achievable good welding profile can improve the fatigue life dramatically. With the help of welding profiles, offshore engineers can achieve a more efficient design of the structure.

1982 ◽  
Vol 1 (18) ◽  
pp. 136
Author(s):  
Ralph R. Clark

Since 1957, the State of Florida, U.S.A., has witnessed the evolution of coastal regulatory concepts based upon coastal engineering design guidance. In 1978, the Florida Legislature encouraged counties and municipalities to adopt coastal construction zoning and building codes to supplement the existing minimum codes which include the Standard Building Code, the National Building Code and the South Florida Building Code. Subsequently, coastal building code guidelines were developed to provide statewide uniformity in the adoption of supplemental codes by coastal counties and municipalities. It is the intent of this paper to present the structural design aspects required in a coastal building code using the code guidelines developed for and specifically applicable to Florida's coastal communities. These same design aspects and code guidance are applicable to most other state's or nation's developable sand shorelines which are subjected to coastal storm damage. The purpose of a coastal building code in Florida communities is to supplement the existing minimum code by providing the structural design standards for construction within that portion of the beach and dune system which is subject to substantial scour, erosion, flooding, and loads accompanying the impact of a major hurricane. A coastal building code includes structural design standards for the construction of residential structures, enclosed commercial structures, coastal and shore protection structures, and other substantial structures of a semi-permanent nature. Although the few minimum codes currently in effect in the coastal communities are comprehensive for conventional construction, they do not adequately address the special structural design considerations identified for the Florida coast. Along a developable coast, special design considerations are necessary for the preservation of the beach and dune systems, as well as, for the structural adequacy of the construction. The major concepts of coastal engineering design which are necessary in a coastal building code include: 1. Zone identification (horizontal and vertical). 2. Foundation design for erosion and scour. 3. Storm loading (including wind, waves, hydrostatic, and hydrodynamic loads).


2012 ◽  
Vol 159 ◽  
pp. 272-276
Author(s):  
Shi Qing Lu ◽  
Han Bin Xiao ◽  
Ping Deng

This paper presents an approach to evaluate the structural fatigue life of port cranes. Based on a testing of 40t/45m container crane in a port of China, the stress time-history collection, data processing, the determination of S-N curve and the distribution of the load amplitude is analyzed in detail. Finally, the modified linear cumulative damage law is employed to evaluate the remaining safety service life of the container crane. The result of this study can be a reference for the anti-fatigue structural design of cranes, and it also provides a guideline for ports’ management and maintenance departments to make maintenance plans for port cranes.


2014 ◽  
Vol 620 ◽  
pp. 100-103
Author(s):  
Heng Li Liu ◽  
Bao Shun Liu ◽  
Xiao Na Li

For products, the structure determines function; appearance form aesthetic; and the two co-exist to achieve the perfect unity of function and aesthetics, but in fact, the structure is largely affects the product shape. In this paper, classified the product structure according to function, analyzed the impact of the typical structural design to the shape of product, and also pointed out that the development of science and technology and material choice are also an important factor in the structure design, thereby affected the design of the product styling. By analyzing, it elaborated fully the impact of structural design and its importance in the product design, and provided one practical way of thinking.


2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.


2021 ◽  
Vol 11 (9) ◽  
pp. 4071
Author(s):  
Yali Zhang ◽  
Xinrong Huang ◽  
Yubin Lan ◽  
Linlin Wang ◽  
Xiaoyang Lu ◽  
...  

Aerial electrostatic spray technology for agriculture is the integration of precision agricultural aviation and electrostatic spray technology. It is one of the research topics that have been paid close attention to by scholars in the field of agricultural aviation. This study summarizes the development of airborne electrostatic spray technology for agricultural use in China, including the early research and exploration of Chinese institutions and researchers in the aspects of nozzle structure design optimization and theoretical simulation. The research progress of UAV-based aerial electrostatic spray technology for agricultural use in China was expounded from the aspects of nozzle modification, technical feasibility study, influencing mechanism of various factors, and field efficiency tests. According to the current development of agricultural UAVs and the characteristics of the farmland environment in China, the UAV-based aerial electrostatic spray technology, which carries the airborne electrostatic spray system on the plant protection UAVs, has a wide potential in the future. At present, the application of UAV-based aerial electrostatic spray technology has yet to be further improved due to several factors, such as the optimization of the test technology for charged droplets, the impact of UAV rotor wind field, comparison study on charging modes, and the lack of technical accumulation in the research of aerial electrostatic spray technology. With the continuous improvement of the research system of agricultural aviation electrostatic spray technology, UAV-based electrostatic spray technology will give play to the advantages in increasing the droplets deposition on the target and reducing environmental pollution from the application of pesticides. This study is capable of providing a reference for the development of the UAV-based agricultural electrostatic spray technology and the spray equipment.


Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ammar Ali Abd ◽  
Samah Zaki Naji ◽  
Ching Thian Tye ◽  
Mohd Roslee Othman

Abstract Liquefied petroleum gas (LPG) plays a major role in worldwide energy consumption as a clean source of energy with low greenhouse gases emission. LPG transportation is exhibited through networks of pipelines, maritime, and tracks. LPG transmission using pipeline is environmentally friendly owing to the low greenhouse gases emission and low energy requirements. This work is a comprehensive evaluation of transportation petroleum gas in liquid state and compressible liquid state concerning LPG density, temperature and pressure, flow velocity, and pump energy consumption under the impact of different ambient temperatures. Inevitably, the pipeline surface exchanges heat between LPG and surrounding soil owing to the temperature difference and change in elevation. To prevent phase change, it is important to pay attention for several parameters such as ambient temperature, thermal conductivity of pipeline materials, soil type, and change in elevation for safe, reliable, and economic transportation. Transporting LPG at high pressure requests smaller pipeline size and consumes less energy for pumps due to its higher density. Also, LPG transportation under moderate or low pressure is more likely exposed to phase change, thus more thermal insulation and pressure boosting stations required to maintain the phase envelope. The models developed in this work aim to advance the existing knowledge and serve as a guide for efficient design by underling the importance of the mentioned parameters.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Qing-liang Zeng ◽  
Zhao-sheng Meng ◽  
Li-rong Wan ◽  
Cheng-long Wang

To study the load transfer characteristics of a two-legged shield powered support, a numerical simulation model of the support was established using the multibody dynamics software ADAMS. The model took full account of the hydraulic-elastic deformation characteristics of the support, as a series spring-damper system was used to replace the leg and the equilibrium jack. The canopy, goaf shield, lemniscate bars, and equilibrium jack are equivalent to flexible bodies. The setting force of the leg was provided by the preload of the equivalent spring, the static roof load was simulated using a slope signal, and the impact load was simulated using a step signal. Using the model, the impact and excitation effects of each hinge joint of the support were analyzed under different impact load conditions across the canopy. The results show that the location of the impact load affects the force transmissions of all hinge points of the support. Both the impact effect and the excitation effect are at a minimum when the impact force is located near the leg action line. These results are useful for the adaptive control and structural design optimization of the support.


Author(s):  
Miloš Pjević ◽  
Ljubodrag Tanović ◽  
Goran Mladenović ◽  
Biljana Marković

The paper presents experimental results of microcutting brittle materials (granite). The analysis was conceived on the observed interaction between the workpiece and two tools of different shapes. Experiment was based on scratching the workpiece surface with diamond tools. Applied tools had tip radius R0.2 and R0.15 mm. The experiment determined the changes in the value of perpendicular and tangential components of the cutting force based on the geometric properties of tools, as well as the changes of the specific energy of microcutting granite (Jošanica and Bukovik types). The experiment has shown that reduction of tool radius causes reduction of the cutting force intensity and specific cutting energy. Because of its physical/mechanical properties, more energy is required for micromachining granite “Jošanica” than “Bukovik.” Based on the topography of the surface, the value of critical tool penetration depth was established, after which the brittle fracture is no longer present. For granite “Jošanica” values of critical penetration depth are 6 and 5 μm when micromachining with tools R0.2 and R0.15 mm, while for Bukovik those values are 6.5 and 5.5 μm. The paper should form the basis for understanding the phenomena which occur during microcutting brittle materials.


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