Model 3D Desain Struktur Baja Canai Dingin pada Rumah Sederhana 2 Lantai Berdasarkan SNI 7971-2013. (Hal. 9-17)

2018 ◽  
Vol 4 (2) ◽  
pp. 9
Author(s):  
Muhammad Ahdi Hafizha ◽  
Kamaludin Kamaludin

ABSTRAKIndonesia adalah negara berkembang dengan pertumbuhan pembangunan yang cukup tinggi, sementara luas lahan yang tersedia masih tetap dan terbatas. Akibat dari kondisi tersebut, berdampak pada kebutuhan akan rumah tinggal atau hunian akan semakin tinggi, Rumah sederhana 2 lantai yang layak dan kokoh berbasis ekonomis adalah solusi untuk masyarakat tersebut. Profil baja canai dingin adalah jenis profil baja yang memiliki ketebalan dimensi yang relatif tipis dengan rasio dimensi lebar setiap elemen profil terhadap tebalnya sangat besar, karena ketebalan dimensi profil relatif tipis, maka pembentukan profil dapat dilaksanakan menggunakan proses pembentukan dingin. Maka dari itu adanya model rumah sederhana 3D menggunakan profil baja canai yang praktis dan relatif murah adalah solusi masalah tersebut. Peneliti mengkhususkan mengetahui perbandingan gaya dalam dan rasio yang terjadi  pada model struktur 2D dan 3D. Hasil yang Didapat dari rasio balok yaitu 0,98 dan kolom 0,69.Kata kunci: baja canai, rumah, balok, kolom. ABSTRACTIndonesia is a developing country with relatively high development growth, while the available land area is still limited. As a result of these conditions, the impact on the need for residential or occupancy will be higher, simple and economically viable 2-storey house is a solution for the community. The profile of cold rolled steel is a type of steel profile that has a relatively thin dimensional thickness with the width dimension ratio of each profile element to a very large thickness. Because the profile thickness thickness is relatively thin, the profile formation can be performed using cold forming process. Therefore the existence of a simple 3D home model using a practical and relatively cheap steel roll profile is the solution of the problem. The researcher specializes in knowing the inner force ratio and the ratios that occur in 2D and 3D structural models. The results obtained from beam ratios are 0.98 and 0.69 columns.Keywords: cold formed, house, beams, coloum.

2013 ◽  
Vol 631-632 ◽  
pp. 708-712
Author(s):  
Bong Joon Kim ◽  
Eun Soo Park ◽  
Won Yong Byeon ◽  
Dal Joon Cha ◽  
Yong Nam Kwon

In this study, cold reduction process of the tubular metal is applied to manufacture the drive shaft for the rear wheel drive system. With this method during forming process, chip forming such as hobbing and broaching method is not involved. The manufacturing process is as follows; the tube which the sheet is formed and welded to by roll forming machine, is mounted on a suitable mandrel. This mandrel has an external toothing which corresponds to internal toothing of the final product. During axial moving and rotating of the workpiece, forming operation is carried out in lengthwise direction of the toothing. This forming rolls is positioned on the roll head and have a rolling axis vertical with the one of a mandrel. The total forming load needed in the cold reduction process is separated into numerous forming steps along the entire cylindrical length of the zone to be formed. In the process of cold forming on the profiled mandrel during the impact forming operation, material is pushed into depression of toothing of a mandrel mainly in a radial direction. Finally splines can be generated on the surface of components and overall elongated. If the process parameter such as the length of forming per 1rotation of 1roll is not optimized, the impact force from the rolls of the forming process causes geometrical defects. So the optimal parameters such as feeding and rotating speed of workpiece and the forming length should be properly determined. And the effects of the weld line positioning on the formability of the forming process is analyzed to minimize the generation of the defects such as crack on the surface of splined zone.


Author(s):  
Luciano O. Mantovano ◽  
Mohamed R. Chebaro ◽  
Hugo A. Ernst ◽  
Marcos de Souza ◽  
Chris M. Timms ◽  
...  

The UOE-SAWL pipe manufacturing process introduces considerable plastic deformations and residual stresses to feedstock plate material. Previous experimental and analytical studies have demonstrated that the effects of this process, predominantly in its final expansion stage, significantly reduce the collapse resistance of deepwater linepipe. Finite element analyses, sensitivity analyses and full-scale tests were conducted by Tenaris and C-FER Technologies (C-FER) over the last several years to better comprehend the impact of cold forming on collapse resistance. This paper presents the findings of the latest segment of this ongoing study, the objective of which was to optimize the collapse resistance of UOE-SAWL linepipe by varying three key thermal ageing parameters: time, temperature and number of thermal cycles. Six X70M and four X80M UOE pipe samples were manufactured and thermally treated with varied parameters. Full-scale collapse and buckle propagation tests were then carried out in an experimental chamber that simulates deepwater conditions. These experimental results were evaluated with respect to collapse predictions from API RP 1111 and DNV OS-F101. Material and ring splitting tests were also performed on samples obtained from these pipes to better assess the extent of the UOE pipe collapse resistance recovery. The outcomes of this study will be employed to further optimize the collapse resistance of subsea linepipe in order to reduce material and offshore installation costs.


2020 ◽  
Vol 846 ◽  
pp. 53-57
Author(s):  
Min Heo ◽  
Min Sik Lee ◽  
Hyeong Yun Seo ◽  
Chung Gil Kang

Recently, automobile components such as center pillars and impact beams have been fabricated using materials that satisfy both high strength and impact absorption. In this study, the forming process of CR340 (cold rolled steel)/CFRP hybrid composites was investigated. Initially, hybrid composites were fabricated by stacking carbon fibre reinforced plastic (CFRP) prepreg on CR340 steel with Zn coating. An adhesive agent developed by the research team was applied for bonding between the cold rolled steel and CFRP to enable the blank fabrication of hybrid composites. The mechanical properties of the developed hybrid composites were investigated by tensile, bending and lap shear adhesion test. The results showed that the tensile strength and shear strength of composites increases with the increase in the number of laminations but the bending strength decreases.


2021 ◽  
Vol 349 ◽  
pp. 04005
Author(s):  
Boris Spak ◽  
Maximilian Schlicht ◽  
Karina Nowak ◽  
Markus Kästner ◽  
Pascal Froitzheim ◽  
...  

Joining by forming is a commonly applied technique in the automotive industry to assemble parts of thin metal sheets to meet the demands of lightweight design. The joining operation induces changes in material behaviour due to cold forming, that can be observed in increased hardness in the area close to the joint neck compared to the base material. Complex geometrical features of clinched joints on a small scale and the lack of non-destructive methods to track local stresses and strains require a combined approach utilizing numerical and experimental techniques. Numerical process and loading simulation are performed utilizing commercial finite element software LS-Dyna®. Hardness measurements in the joint are carried out to assess the impact of forming operation. Cyclic material properties are derived from Vickers hardness to estimate fatigue life with the Local Strain Approach using the damage parameter PSWT. Fatigue life estimation with failure criterion crack initiation obtained from simulation results is compared to those from experiments. The results obtained indicate that the Local Strain Approach is suitable for fatigue life estimations of clinched joints under constant amplitude loading as long as the influence of the forming process is considered.


Author(s):  
Marcos Pérez

Cold rotary forging is an innovative incremental metal forming process whose main characteristic is that the workpiece is only partially in contact with a conical tool, reducing therefore the required forging loads. However, in spite of many benefits of such a process, wide industrial implementation of rotary forging is not possible without proper understanding of material behaviour. In the present work, the capability of rotary forging process was explored for the manufacturing of flared cylindrical parts by cold forming. Another main aim was to assess the cold formability of high-strength materials for aerospace applications (martensitic stainless steels) under incremental processes. In order to understand the impact of rotary forging on the final properties of formed components, microstructural and mechanical analysis were performed. Microstructural and hardness analysis were conducted on both axial and transverse sections along the cold formed flange in order to study the grain flow orientation and strain distribution. In a similar fashion, mechanical test specimens were machined from different positions and orientations along the rotary forged component. Further analysis was performed on the components in the as-treated condition in order to understand the response of cold-worked Jethete M152 components to subsequent heat treatments. Microstructural and hardness analysis clearly reveals a strong grain reorientation and strain localization around “pickup“ defects (material attached to the upper tool) observed on the flange top surface, close to the flange edge. These results suggest that an excessive deformation is localized during the early stages of the flange formation. Another characteristic feature found in the rotary forged parts is the presence of a buckling phenomenon which appears in later stages of the rotary forging process. Strain hardening along with the increasing flange length requires higher levels of forging loads to keep forming the flange. This results into a significant accumulation of compressive stresses in the transition region between the flange and the straight region. Gradually the resultant compressive force exceeds the critical buckling load, leading to the occurrence of the buckling phenomenon. This latter issue determines the limit of the cold flaring process. This can help to determine the maximum length of the flange part, achievable in this process, which is of great importance for the design of these manufacturing technologies. From the mechanical testing results, large differences were found as a function of both position and orientation (axial, transverse) throughout the rotary forged components (anisotropic properties). Concerning the impact of heat treatments on cold-worked components, no differences were found in the as-treated condition, in terms of microstructural and mechanical properties between regions with a large difference in strain distribution. These results denote the normalizing effect of conventional hardening treatments on cold-worked Jethete M152 components, restoring the homogenous and isotropic properties across the whole component.


2017 ◽  
Vol 1 (1) ◽  
Author(s):  
La Ode Jabuddin ◽  
Ayub M Padangaran ◽  
Azhar Bafadal Bafadal

This study aims to: (1) Knowing the dynamics of fiscal policy and the performance of the agricultural sector, (2) Analyze the factors that influence fiscal policy and the performance                   of the agricultural sector, and (3) Analyzing the impact of fiscal policy on the performance of the agricultural sector. The data used in this study were pooled 2005-2013 data in the aggregate. Econometric model the impact of fiscal policy on the performance of the agricultural sector is built in the form of simultaneous equations, consisting of 7 equations with 25 total variables in the model, 7 endogenous variables, 12 exogenous variables, and 6 variables lag. The model is estimated by 2SLS method SYSLIN procedures and historical simulation with SIMNLIN procedure.The results showed that: (1) The development of fiscal policy in Southeast Sulawesi from year to year tends to increase, (2) The performance of the agricultural sector from the aspect of GDP has decreased, from the aspect of labor is still consistent, in terms of investment to grow positively, and assign roles which means to decrease the number of poor people, (3) factors affecting fiscal policy is local revenues, equalization funds, other revenues, as well as the lag fiscal policy, (4) the factors that affect the performance of the agricultural sector from the aspect GDP is labor, direct expenditure and GDP lag; from the aspect of labor is the total labor force, investment, land area, direct expenditure, as well as the lag of labor; from the aspect of investment is influenced by GDP per capita, land area, interest rates and investment lag; as well as from the aspect of poor people, are affected by population, investments, direct expenditure and poverty lag, (5). Fiscal policy impact on the agricultural sector GDP increase, a decrease in the number of poor, declining agricultural laborers, and a decrease in the amount of investment in the agricultural sector.Keywords: Fiscal policy, the performance of the agricultural sector, the simultaneous equations


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