本篇代写论文-航空航天工业讲了在航空航天工业，重点是创造制造和焊接过程是非常低的成本和能源效率(Hesselgreaves, 2001)。作为研究背景介绍部分,该行业正专注于成为运营效率的背景下制造业的翼肋和很大一部分的翼肋翼因此成为总面积的重量集中在(Vairis &霜,1998)。由于采用的原钢坯为单件实心钢坯，在加工过程中会产生较大的浪费，因此提出了生产效率低的问题。焊接技术的形式也造成了浪费。本篇代写论文文章由新西兰第一论文 Assignment First辅导网整理，供大家参考阅读。
The project aims to critically analyse the strength of wing rib foot with a Linear Friction Weld LFW in the aerospace industry. A finite element method is made use of for the prediction and assessment of strength.
The objectives of the research are as follows,
To present a fine element model for predicting and assessing the strength and behaviour in LFW rib foot.
To assess the LFW joint in terms of mechanical properties, requirements of the aerospace industry, and relative comparisons to other joints.
To present a valid numerical model that could be used as a base for analysing operational efficiency in rib foots and joints.
Friction Welding: A form under Solid State Welds
2.4. Welding Defects
In the aerospace industry, the focus is on creating manufacturing and welding processes that are very cost and energy efficient (Hesselgreaves, 2001). As presented in the research background section, the industry is focused on becoming operationally efficient in the context of manufacturing of its wing ribs and the wing ribs that are a significant portion of the weight of the total wing hence become an area to focus on (Vairis & Frost, 1998). High inefficiency concerns are introduced here as the original billet used which is a single solid one would get machined off in much wastage. The form of welding technology also contributes to the wastage (Vairis & Frost, 1998). Consider for instance, the forms of welding defects are introduced in the conventional processes. In the conventional welding processes, most of the defects observed are because of the improper application of the process. Some major defects noticed in the aerospace and associated industries are improper welds. In some situations, there are defects or discontinuities that challenge the quality of welding. Porosity, inclusion, fusion penetration concerns, weld profile, cracks and other issues of surface damage are present. This challenges the integrity and quality of the entire weld. The very purpose of adding strength and joint surface structure is hence challenged here. Where there is a high level of porosity, then there are much gas pores that are found in the solidified weld bead. These pores do not have a structure which could facilitate their overall impact on strength, but they are rather randomly dispersed in their settings (Nicholas & Thomas, 1998). This randomness in distribution makes assessment of strengths quite uncertain. In some cases, the porosity is found directly in the centre of the wed. Such issues lead to direct surface damage as well. When pores exist in a wed surface it is not just the pores that challenge the strength, it is also the form of contamination which the pores are subject to that results in issues. For instance, slag inclusion concerns are usually cited in most of the mechanic industries. The slag inclusion along with the issues of porosity challenges most conventional welding procedures (Nicholas & Thomas, 1998). Slag inclusion happens along continuous and discontinuous lines of the weld and usually is associated with the flues processes along the line. Inclusions happen more often because of the molten slag that flats to the surface of the weld. These are not entrapped (Nicholas & Thomas, 1998).