著者

石川 諭 近藤 孝広 松崎 健一郎 榎元 啓允

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.80, no.814, pp.DR0166-DR0166, 2014 (Released:2014-06-25)

参考文献数

10

被引用文献数

1

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A pressure wave generated by a compressor propagates in an air-conditioner piping system and causes a noise problem. The flow condition in the air-conditioner piping system becomes often a one-component two-phase flow, and attenuation of the pressure wave in the one-component two-phase flow is larger than the two-component two-phase flow because of the effect of the mass transfer. It is also important for the safety of nuclear reactors to understand the characteristic of pressure wave problems in the one-component two-phase flow. In this paper, we propose a concentrated mass model to analyze the pressure wave problems in the one-component two-phase flow. This model consists of masses, connecting springs, connecting dampers, and nonlinear base support dampers. The connecting spring and the connecting damper are derived from the compressibility of the gas phase and the effect of the mass transfer when the phase-change occurs. And the nonlinear base support damper is derived from the pipe friction. Additionally, an experiment on an air-conditioner piping system is performed, and the experimental results are compared with the numerical result in order to confirm the validity of the model. The numerical computational results agree very well with the experimental results. Especially, the attenuation of the pressure wave generated by the phase-change is numerically reproduced. Therefore, it is concluded that the proposed model is valid for the numerical analysis of the pressure wave problem in the two-phase flow.

著者

尾形 和哉 柳川 洸哉 大嶋 和彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00194-17-00194, 2017 (Released:2017-09-25)

参考文献数

8

被引用文献数

1

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Gyro actuator is often used for the posture control of systems which cannot be supported on a fixed ground. The gyroscopic moment makes preccesion movement of the gimbal mechanism and its effect depends on the rotating speed of the wheel. In this paper, the accurate dynamic model is derived for bicycle with twin gimbal mechanism considering ups and downs of the ground, which causes the disturbance to the bicycle. It turns out that the effect of the undulations of the ground is cancelled if the rotating speed of the wheels of the twin gimbal are exact the same. Then the stability of this model without feedback control is discussed. This model has fourth order characteristic polynomial and the characteristic roots for the first and the second modes are derived through lower order approximation. The first mode is unstable and the second mode is stable if there is a viscous friction in the gimbal rotation axis bearing. Simulation and experimental results show that the parameters should be designed so that the amplitude ratio of the gimbal pitch angle with regard to the cart roll angle for the first mode may become small to keep the posture of the bicycle for a longer time. This analysis method can be used for a simple feedback control system of the bicycle to evaluate the design parameters of the mechanism and control.

著者

吉原 拓実 志垣 俊介 倉林 大輔

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00108-17-00108, 2017 (Released:2017-09-25)

参考文献数

19

被引用文献数

1

---

Searching an odor source is a challenging task for a distributed autonomous mobile robot due to the complexity of odor formation in the air. Because the shapes of odor plumes highly depend on the environmental conditions including dynamical changes of wind direction, a robust performance of searching is highly demanded. In this paper, we introduced an olfactory active sampling device that was equipped electronic fan to generate air current and suction olfactory information to the sensors. Our main contribution was proposing and evaluating adaptive sampling strategies for appropriate odor-searching behavior in real environments by using the device. The active sampling device was designed after observations of the wing-flapping-effect of a male silkworm moth, which corresponding to‘ sniffing ’of mammals. The device was composed of an electronic fan, two (left and right) gas sensors embedded in air ducts, and was attached to a mobile robot. Each duct had a flange so as to take the air in front of a robot effectively, and the electric fan attached on the end of the duct excluded odors incoming from the rear. We settled different environmental conditions in which the fluctuation of the air flow was changed. We conducted experiments to verify the feasibility of the adaptive sampling system. As a result, under most of the environments, the robot with active sampling showed better performance than that without active sampling. However, the result showed that optimal active sampling has environmental dependency. To realize more adaptive system, we suggested that it is necessary to change the activeness of inspiration depending on the situation.

著者

久保田 淳

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演資料集

巻号頁・発行日

vol.2005, 2005

著者

髙橋 新吾 中村 哲夫 有馬 祐杜 橋本 秀紀 中村 壮亮

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00035-17-00035, 2017 (Released:2017-09-25)

参考文献数

9

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This paper proposes an electrocardiogram (ECG) measuring system which simultaneously enables the reduction of input impedance and low-frequency cutoff through virtual amplification of the coupling capacitance formed by body capacitance and ECG electrode. This virtual amplification of the coupling capacitance is realized by the additional circuit which controls the inflow of external current to create the situation as if the time constant of the capacitance has increased. Moreover, not only this additional function but the amplification circuits commonly used in ECG measuring system has also been perfectly tuned-up. Here, instead of using the MOS-FET which shows bad noise characteristics, the combinations of J-FET differential amplifier and current feedback circuit have been used for stable amplification. In addition, coupling capacitors of the system are removed due to the DC-Coupling enabled by using single operational amplifiers instead of instrumentation operational amplifiers.

著者

松永 充弘 中澤 和夫

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00016-17-00016, 2017 (Released:2017-09-25)

参考文献数

20

---

In resent year, the demand for the autonomous mobile robots which can navigate indoor environment, such as office room, warehouse, hospital has increased. Autonomous mobile robot needs some information to navigate various environment. Self position is one of the important information since the robots need to determine its any behaviors such as path planning. Unfortunately this information is including some critical error such as odometry error which is caused by wheel slipping and uncertainty of its model parameters. Scan match is one of the method to overcome this problem. By determining two point cloud data measured by sensor (such as LIDAR) mounted on robot at different measurement point, it can estimate such errors. And furthermore, scan match is used to improve the proposal distribution of Rao-Blackwelized Particle filter using grid map. However, the computational cost of scan match is higher because searching nearest neighbor need a large amount of computational resources. To overcome this problem, we propose high efficient scan match method, using likelihood field map and hill-climb approach. And then we also propose efficient likelihood mapping method concurrently. In our experiments, efficiency of our scan match method was higher than two conventional method, ICP and correlative matching. And it verified that our likelihood field mapping method efficiency has been improved.

著者

阿部 有貴 小笠原 亮大 尾崎 功一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.16-00572-16-00572, 2017 (Released:2017-09-25)

参考文献数

15

---

This paper discusses a micro manipulation considering that an approach angle on pickup affects adhesion and mechanical balance on release by using two needle-shaped end-effectors. In micro-scale, adhesion is generated by capillary, van der Waals and electrostatic besides gravity. Accurate and repeatable pick-and-release/place of micro sized objects is a long-standing challenge due to the strong adhesion in micro manipulation. We first introduce a strategy of pickup and release of a micro sphere. The strategy features in that the approach angle on pickup decides release by two conditions: one is geometrical condition between the sphere and a tip of end-effector, and the another is mechanical condition by forces (adhesion, gravity and friction) to the sphere from the tip and a substrate. To confirm the efficacy of the strategy, the micromanipulation tests with different approach angles have been conducted. Finally, we show the experimental results by pickup and release of spherical glass beads and not spherical pollens, for confirming the validity of the proposed strategy as a novel manipulation method.

著者

川添 裕三 橋本 英樹 森上 修 村瀬 英一 古川 純一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00159-17-00159, 2017 (Released:2017-09-25)

参考文献数

8

被引用文献数

1

---

To explore the behavior of near-extinction flamelets in turbulent premixed flames, emission intensities of OH, CH and C2 radicals of hydrocarbon-air premixed flames have been examined using the newly developed emission spectroscopy system. It has been shown in our previous study that the emission intensity ratio of 515.5 nm/470.5 nm bands of C2 radical uniquely depends on the temperature of unstrained methane/air and propane/air flames. In the present study, to establish the technique that estimates the temperature of the near-extinction flamelet of turbulent premixed flames, the relation between the temperature and the emission intensity ratio of 515.5 nm/470.5 nm bands of C2 radical of strained flames has been sought by using a counter-flow burner. The unique relation between the flame temperature and the emission intensity ratio of 515.5 nm/470.5 nm bands of C2 radical has been found to exist for the Propane-air and the Butane-air strained flames. Therefore, it can be concluded that the temperature of flamelets of the Propane-air and the Butane-air turbulent premixed flames can be estimated by using the relation between the temperature of the strained flame and the emission intensity ratio of 515.5 nm/470.5 nm bands of C2 radical obtained in the present study.

著者

古口 日出男 佐藤 広美 前川 富哉 Chonlada Luangarpa

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00198-17-00198, 2017 (Released:2017-09-25)

参考文献数

15

---

Singular stress and electric displacement fields occur at the vertex of interface in piezoelectric joints under an external loading. It can be expected that concentrated electric displacements causes large electric fields in an adjacent space and electric potential will be induced on the surface of electrode when the electrode approaches to the electric field. In the present paper, a piezoelectric joint which four blocks of piezoelectric material are bonded using a resin is analyzed. In this joint, a singular field occurs at a center gathering four vertexes in blocks and the intensity of singularity in electric displacements around the center of cross section in the joint may be four times larger. The intensity of singularity is numerically investigated using several methods for analysis to pursue the possibility of application of the singular fields. Firstly, three loading conditions, e.g., compression in the poling direction, compression in the vertical direction of side surface and input a voltage, are investigated for increasing a response of electric displacement in the piezoelectric joint. In the case of compression in the vertical direction of side surfaces, the maximum response is obtained. Hereafter, the results in the analyses are obtained for the compression of vertical direction of side surface. It is shown that the intensity of singularity depends on a power law of the thickness of adhesive layer. Influence of material properties of adhesive layer, piezoelectric and dielectric properties in the block of the joint, on singular fields is also investigated. It is shown that when piezoelectric materials with large piezoelectric constant are used, amplified electric displacements are obtained.

著者

迫 洋介 吉村 英徳 三原 豊 石橋 賢樹 浜本 英利 福井 優

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集

巻号頁・発行日

vol.2010, pp.173-174, 2010

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A fabrication method of a painless transdermal micro needle array is proposed to realize its inexpensive and mass production. In order to avoid a risk by breakage of the needle when the needle is penetrated into the epidermis, the array is made with biodegradable polymer, for example, PLA. The proposed method has the following processes, (1) a mold dies having many micro through-holes is heated over the melting point of PLA, (2) the heated mold comes into contact with surface of the PLA plate, (3) the melted PLA is poured into the through-holes, and (4) the formed PLA plate is cooled to less than the melting point and removed from the dies. It is difficult to fabricate the array device because of the ratio of needle height to the diameter is large. So, heating temperature, time of heating the plate, moving stroke of dies and demolding temperature were examined and then fabrication of high precision circular cylindrical shaped needle array became possible.

著者

國分 朋之 祖山 均

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00190-17-00190, 2017 (Released:2017-09-25)

参考文献数

24

被引用文献数

1

---

Peening techniques are used to introduce the compressive residual stress into the surface of metallic materials in order to improve the fatigue properties. The fatigue crack propagation is affected by many factors in surface modification layer, however, the effect of these factors on the fatigue crack propagation is not clarified in detail. In this study, the fatigue crack propagation behavior in surface modification layer of duralumin treated by various peening techniques including shot peening, cavitation peening and laser peening was investigated. The relationship between the fatigue crack propagation behavior and mechanical properties was also evaluated. The fatigue crack propagation behavior varies depending on peening techniques despite the condition of the same peening intensity, since the mechanical properties in surface modification layer are changed with the peening techniques. The compressive residual stress σR and Vickers hardness HV are the important factors about fatigue crack propagation, however they do not show a correlation with the number of cycle to failure of the specimen Nf. Therefore, the new indicator combined with four factors i.e. σR, HV, full-width at half maximum β and maximum height roughness Rz were proposed. It revealed a significant correlation with Nf, and possibility to evaluate the effect of suppression of fatigue crack propagation by peening.

著者

近藤 義広 松下 伸二 森山 隆志 大橋 繁男

出版者

一般社団法人 日本機械学会

雑誌

年次大会講演論文集

巻号頁・発行日

vol.2000, pp.171-172, 2000

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We have developed a method of cooling high-power-density CPU modules within a bending duct. The method uses a jet-duct system made of an air duct and axial fans. This system has slit orifices upstream from the CPU modules. Pressure drops in this system are calculated as four values : wringing loss in the chamber, friction loss in the duct, extrusion loss from the duct, and wringing loss in the slit orifice. These loss values agree with the experimentally measured losses to within an error of ±10%. The calculation showed that when the duct width is small, the wringing loss in the chamber account for the major part of the total loss.

著者

佐藤 運海 川久保 英樹

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00179-17-00179, 2017 (Released:2017-09-25)

参考文献数

14

被引用文献数

1

---

This paper discusses the surface modification processing of kovar alloy (Fe-29.72wt%Ni-16.28wt%Co) by Na2SO4 electrolyzed oxidizing water (hereinafter referred to as EO water). First, the etching effect of Na2SO4 EO water on the surface of kovar alloy was clarified by comparative experiments of chemicals and NaCl EO water. The comparative study showed that as for the etching effect on the surface of kovar alloy, Na2SO4 EO water was superior to H2SO4 solution, but inferior to NaCl EO water. Next, by the observation using SEM image, the influence of Na2SO4 EO water on the surface shape of kovar alloy was clarified. The results indicated that when using Na2SO4 EO water, the surface of polished test pieces which had not been heat-treated becomes smooth, but in the test pieces surface which had been heat-treated, a lot of dimples had occurred. When using the supersonic together with one of Na2SO4 EO water or NaCl EO water, the surface shape became smooth. Lastly, as for the test pieces after heat treatment, the surface oxidation layer removal experiment by the immersion was carried out. The results showed that Na2SO4 EO water could remove the surface oxidation layer like H2SO4 solution approximately. However, thin surface oxidation layer might be formed when using Na2SO4 EO water. By this study, we received the suggestion that Na2SO4 EO water could be applied to the surface treatment such as the etching of kovar alloy.

著者

芦澤 勇暉 岸本 喜直 小林 志好 大塚 年久

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00148-17-00148, 2017 (Released:2017-09-25)

参考文献数

27

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Replacement of a damaged pipe is important to prevent an accident caused by the pipe. The major damage of the pipe in long-term use is pipe wall thinning. Thus, identification techniques of the location and the thickness of the pipe wall thinning are necessary to decide the appropriate time to replace the pipe. The ultrasonic testing (UT) and the radiographic testing (RT) are currently mainstreams in nondestructive inspections. However, the UT requires the surface preparation of the pipe, and the RT has the risk of the radiation leakage. This study has developed a novel technique of nondestructive identification of location and thickness of pipe wall thinning by using magnetic sensor. This technique aims at only nonmagnetic pipes, and estimates the location and the thickness of the thinning part in the pipe by using the measurement data of the magnetic flux density when the electric current is applied into the pipe. Furthermore, the measurement sensitivity of the magnetic flux density is improved by setting the high magnetic permeability material around the magnetic sensor. In order to verify the validity of the proposed technique, numerical simulations and actual experiments were performed by using specimens with several patterns of the location and the thickness of the thinning part. The results show that the direct analysis values agreed with the measurement data. The inverse analysis results show that the estimated values of the parameters to evaluate the thinning part successfully agreed with the correct values in most of the cases in this study. It is believed that the proposed technique can be applied to practical situations.

著者

吉村 博仁 堀田 恭平 星 幸義 永澤 克浩

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00094-17-00094, 2017 (Released:2017-09-25)

参考文献数

15

被引用文献数

1

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In recent years, needs for micro drilling are increasing, accompanying the development of higher wiring density of printed circuit board (PCB). When drilling PCB for the purpose of making the electric through holes, it has been said that the drill breakage is caused by being filled the chips of GFRP and copper of PCB in the drill flutes. The aim of this study is to clarify the effect of PCB drilling using DLC coated drill on tool wear, chip evacuation and cutting torque. Series of drilling tests of PCB have been carried out to investigate the amount of drill wear, the chips evacuation behavior out of drilled hole with the drill, the shape of chips produced and the cutting torque using DLC-coated drill and non-coated drill. The chips evacuation behavior out of drilled hole with the drill is filmed by a high-speed motion camera and the shape of chips produced is observed by a microscope. The cutting torque is measured by a dynamometer; Kistler 9329A. The amounts of drill flank wear and margin wear using DLC-coated drill and non-coated drill are almost the same. The chips of GFRP using DLC-coated drill are shorter and smaller than those using non-coated drill. The chips evacuation out of drilled hole with the drill using DLC-coated drill is better than those using non-coated drill, and cutting torque using DLC-coated drill is lower than those using non-coated drill.

著者

福重 真一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00121-17-00121, 2017 (Released:2017-09-25)

参考文献数

18

被引用文献数

2

---

This paper proposes an interactive image-based re-modeling system for virtual reshaping of real objects via a video see-through display. The system provides a quasi-realistic design environment in which a designer manipulates the shape and location of real products installed in a real living space. A prototype of the proposed system is developed by integrating two sub-systems for solid modeling based on 3D-CAD and visualization based on image-based rendering. A case study of the virtual redesign of real products illustrates that the proposed system allows designers to examine various design changes on the existing products in an immersive and realistic 3D environment.

著者

伊藤 研一郎 西村 秀和 小木 哲朗

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00113-17-00113, 2017 (Released:2017-09-25)

参考文献数

25

被引用文献数

3

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Navigation systems are nowadays widely used for cars though it is yet to be able to say popularized for motorcycles. While motorcycle navigation systems are not popularized yet, previous research indicates motorcyclist's high demand against a useful navigation system. The absence of useful motorcycle navigation system is an issue of current products not capable of providing navigation information efficiently. To work with the issue, information presentation design is necessary to consider the motorcyclist's characterful viewpoint movement of looking at the road surface carefully in a vertical movement. As a solution to this issue, we propose the use of head-up display for information presentation. Previous studies have revealed the amount and positions suitable to present information for motorcyclist while riding, although the timing of information presentation is yet to be discussed. Thus, in this paper, the information presentation timing to provide navigation information has been evaluated. Experiment using an immersive CAVE motorcycle simulator was conducted with the configuration of five timings between 25 m to 85 m prior to the intersection under conditions of urban street with 30 km/h speed limit. Durations of motorcyclist's viewpoint movement and five scale subjective ratings were used for evaluation. The experimental results from 10 subjects showed a statistically significant difference in subjective ratings. In conclusion, suitable information presentation timing of riding in urban streets with 30 km/h speed limit is around 40 m to 55 m prior to the target intersection.

著者

数仲 馬恋典

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00093-17-00093, 2017 (Released:2017-09-25)

参考文献数

24

被引用文献数

2

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In this paper, a mechanism consisted of a double-cone rolling on two divergent-convergent rails is proposed to be used in the construction of a wave-powered electrical generator. Such divergent-convergent rails, attached to a buoy, can be materialized by using either straight V-rails, or eccentric circular rails. Rotational movement of the buoy, induced by the waves, is transformed into the rotational and translational motion of a magnetized double-cone. In this way, a variable magnetic field is extended over several coils, connected in parallel. Power generation is obtained through the electromagnetic induction effect. Firstly, a geometrical model is proposed to determine the length and radii of contact between the double-cone and the circular rails. Variation of the number of rotations, theoretically obtained, versus the rails eccentricity is validated by tests, where a double-cone, made in S45C carbon steel, is rolling on circular rails, made of A5052 aluminum alloy. Then, a model to evaluate the pressure of contact, and the change of potential energy of the double cone, is advanced. Based on such model, variation of the maximal contact pressure versus the rails eccentricity is clarified, for various loading patterns, corresponding to waves of different heights.

著者

平尾 章成 有田 実花子 金 侖慧 松岡 由幸

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00090-17-00090, 2017 (Released:2017-09-25)

参考文献数

16

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Person has spent most of the day in a sitting posture. In recent years, there has been a growing attention to the "seating comfort" researches. However, research topics are complicated and vary widely, it is difficult for a designer to use accurately design knowledge during the development of chairs. Therefore, in this study, "seating comfort" researches based on the literatures were systematically analyzed by the elements extracted and classified into spaces of element inter-relationship diagram using Multispace design model. Extracted elements were classified and discussed about change based on timeaxis. And, also the literatures categorized using cluster analysis of the extracted elements. From consideration based on the analysis results, researches about the human mechanism of seating comfort and long-term sitting analysis including the postural change have been proposed as non-research areas for future knowledge expansion.

著者

朝賀 泰男 西垣 英一 青井 一郎 杉浦 豪軌 槇野 浩司

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.853, pp.17-00088-17-00088, 2017 (Released:2017-09-25)

参考文献数

13

被引用文献数

1

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As manufacturing has begun to move from mass production to mass customization, manufacturing industries are currently constructing the architecture to provide wide variety of products in countries around the world. Modular design and standardization is effective for mass customization. In recent years, modular design techniques have been researched in vehicle development. Then, car manufacturers have been announcing their own architecture about the car design. We have focused on pipe-based components as the standardized member of body structure. Since the pipe is a general-purpose member, we can get them easily. In this study, we have developed new design techniques for body structure consist of the pipe-based standardized components. Firstly, we have designed base frame layout by topology optimization formulated Min-Max approach for multiple load cases. Secondly, we have calculated cross-sectional design parameters by discrete design value table and fully stressed design. Using these techniques based on modular design rules, we can obtain body structure consisting of standardized components which are subjected to stress lower than the yield strength. As a case study, we have applied our unique modular design techniques to the rear body structure model.