• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.13 no.6
• /
• pp.107-113
• /
• 2004

This paper presents the pillar section optimization technique considering the reliability of the vehicle body structure consisted of complicated thin-walled panels. The response surface method is utilized to obtain the response surface models that describe the approximate performance functions representing the system characteristics on the section properties of the pillar and on the mass and the natural frequencies of the vehicle B.I.W. The reliability-based design optimization on the pillar sections Is performed and compared with the conventional deterministic optimization. The FORM is applied for the reliability analysis of the vehicle body structure. The developed optimization system is applied to the pillar section design considering the fundamental natural frequencies of passenger car body structure. By applying the proposed RBDO technique, it can be possible to optimize the pillar sections considering the reliability that engineers require.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.4
• /
• pp.128-134
• /
• 2013

High bending collapse performance (maximum resistance force and mean resistance force) of body center pillar is an important design target for vehicle safety against side impact. In this study, effect of the upper section shape and the thickness of outer reinforcement on bending collapse performance was investigated for the center pillar of a large passenger car. First, through bending collapse analyses using simple models with uniform section, an optimized center pillar upper section was chosen. Next, bending collapse performance for various models of the actual center pillar with changing the thickness of outer reinforcement were analyzed. The finally designed model showed distinctive enhancement in bending collapse performance nearly without weight increase.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.7
• /
• pp.15-23
• /
• 2009

This research area is a greate section of triple tunnels that passes through the fault fractured zone the in the granite area. In this area, tunnel section, pillar width and overburden height are changed consecutively due to declivity of 1 : 4.5 and slope formation of upper part as changed section. That is, stability estimation for each section varying pillar width can be conducted because tunnel diameter changes gradually from 0.5D to 1.0D according to distance of pillar width. We have estimated the stability of pillar width in triple tunnels with monitoring value, and compared the stability with results of numerical analysis.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.6
• /
• pp.133-139
• /
• 2000

Vibrational characteristics of the vehicle structure are mainly influenced by the shape of the pillar cross section. In this paper a vehicle structural optimization technique has been developed to investigate a lightweight vehicle structure subject to constraints on natural frequencies in a simple beam-and-shell model. In this technique, the optimization procedures involve two stages. In the first stage, the section procedures involve tow stages. In the first stage, the section properties of beam elements of the vehicle structure has been optimized to have minimum weight while satisfying the constraints of natural frequencies. And, in the second stage, the shape of the cross section of the elements of the structure has been determined.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.7
• /
• pp.496-499
• /
• 2012

Modified structure of copper pillar bump which has trapezoidal cross section on the top region is suggested with simulation results and concept of fabrication process. Due to the large surface area of joint region between bump and solder in suggested structure, electro-migration effect can be reduced. Reduction of electro-migration is related with current density and joule heating in bump and investigated with finite element methods with variation of dimensional parameters. Mechanical characteristics are also investigated with comparing modified copper pillar bump and conventional copper pillar bump.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.7 no.1
• /
• pp.56-65
• /
• 2007

This paper describes physical meanings of various influences of cavity (or pillar) shape and filling factor of dielectric material on band structures in two-dimensional photonic crystals. Influences of circular and rectangular cross-sections of cavity (or pillar) arrays on photonic band structures are considered theoretically, and significant aspects of square and triangular lattices are compared. It is shown that both averaged dielectric constant of the photonic crystal and distribution profile of photon energy play important roles in designing optical properties. For the triangular lattice, especially, it is shown that cavity array with a rectangular cross-section breaks the band structure symmetry. So, we discuss this point from the band structure and address optical properties of lattice with a circular cross-section cavity.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.04a
• /
• pp.159-162
• /
• 2000

Wrinkles and shape distortions are generated during the forming of B-pillar(or center pillar) which is a component of the automobile side-frame. The stretch flanging modes at the joining part of the B-pillar and the roof-rail or the side-still give rise to forming problems when taior-welded blanks are applied to the side-frames. The authors simplified B-pillar lower part to T shaped section to investigate the forming behaviors. Three of die step locations and two of blank types were tested to show the effects of weld line locations and edge conditions on he forming of tailor welded blanks. The heights of body wrinkles and the strain distribution in the stretch flanged area were measured and compared.

• Journal of KSNVE
• /
• v.5 no.3
• /
• pp.395-402
• /
• 1995

In general low frequency vibration characteristics like an idleshake is mainly influeced by pillar section properties and joints. So the design technique development of vehicle pillar structures is required to initial design and vehicle development stage. In this paper to develop pillar structure design technique considering low frequency vibration characteristics, strain energy method, design sensitivity analysis method, and design optimization method using commercial finite element analysis program and optimization program are presented.

• Geomechanics and Engineering
• /
• v.29 no.6
• /
• pp.697-706
• /
• 2022

In order to explore the stable anchoring conditions of coal side under the mining disturbance of soft section coal pillar in Wangcun Coal Mine of Chenghe Mining Area, the distribution model of the anchoring support pressure at the coal pillar side was established, using the strain-softening characteristics of the coal to study the distribution law of anchoring coal side support pressure. The analytical solution for the reinforcement anchorage stress in the coal pillar side was derived with the inelastic state mechanical model. The results show that the deformation angle of the roadway side and roof increases with the roof subsidence due to the mining influence at the adjacent working face, the plastic deformation zone extends to the depth of the coal side, and the increase of anchorage stress can effectively control the roof subsidence and further deterioration of plastic zone. The roadway height and the peak support pressure have a certain influence on the anchorage stress, the required anchorage stress of the coal side rises with the roadway height and the peak support pressure. The required anchorage stress of the coal pillar side decreases as the cohesion between the coal seam and the roof and floor and the anchor length increases. Then, applied the research result to Wangcun coal mine in Chenghe mining area, the design of anchor cable reinforcement support was proposed for the section of coal pillars side that has been anchored and deformed, which achieved great results and effectively controlled the convergence and deformation of the side, providing a safety guarantee for the roadway excavation and mining.

• International conference on construction engineering and project management
• /
• 2009.05a
• /
• pp.808-813
• /
• 2009

Top-down method is widely used for urban area construction for its advantages in reducing environmental problems such as dust and noise, and saving construction cost depending on given conditions of a construction site. Because the excavation and construction of super- and sub-structures of the building have to be proceeded simultaneously, a column has to be embedded prior to excavation. This column is called a pillar column or pre-founded column. Usually a wide flange section is used for these columns. To place the columns, usually the diameter of casing holes needs to be larger than the section of the wide flange itself in order to accommodate a couple of tremie pipes for pouring concrete. In this paper, a newly developed method of using circular pipe as an alternative to the existing wide flange section is discussed. The crucial part of the new method is to develop a connection between the circular column and concrete flat slabs. For shear force transfer from concrete slab to the concrete filled tube (CFT) column, shear jackets with studs and shear bands are proposed. The studs are welded on the jackets at shop and placed around the circular column on site. The shear bands are welded on the outer side of the CFT at shop and inserted into ground with the CFT. Test results and application of the method to a construction site are also provided in this paper.