• Title/Summary/Keyword: 정면도

Search Result 715, Processing Time 0.029 seconds

구조용 FRP부재의 적층구성이 흡수에너지특성에 미치는 영향

  • 최효석;김영남;양인영
    • Proceedings of the Korean Institute of Industrial Safety Conference
    • /
    • 1999.06a
    • /
    • pp.25-30
    • /
    • 1999
  • 자동차의 정면 충돌시 발생하는 충돌에너지를 흡수하여 인명을 보호하기 위한 장비중 구조 역학적 관점에서 고려될 수 있는 것으로 범퍼와 사이드멤버(Side Member)가 있다. 이들중 범퍼는 시속 8km/hr 이하의 저속 충돌시에 탄성 변형에너지로서 충돌에너지를 흡수하는 역할을 하나, 그 이상의 고속 정면 충돌시에는 일반적으로 사이드멤버가 충돌에너지의 60∼70%를 부재의 연속적인 대변형에 의한 소성에너지에 의해 흡수하고 있다. (중략)

  • PDF

정면밀링작업에서의 최적절삭조건 선정

  • 소환철;김희술
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1993.04b
    • /
    • pp.61-65
    • /
    • 1993
  • 절삭작업에 있어서 생산기술자가 제품을 경제적으로 생산하기 위해서는 기계의 사양이나 요구되는 제품의 정밀도 등 을 고려하여 목적에 맞는 절삭조건을 선택하여야 한다. 특히 임금이 과거에비해 크게 오르고 기계의 가격이 자동화로 인하여 고가가 됨에 따라서 기계의 효율적 운용이 점점 더 중요하게 되었다. 따라서 목적에 맞는 절삭조건의 선정은 기업의 경쟁력 향상에 있어서 중요한 문제로 부상되고 있다. 본 논문에서는 정면밀링작업시, 인서트 초기위치오차( Runout)를 고려한 표면조도와 절삭력 시뮬레이션 프로그램을 이용하여 구한 허용동력을 제한조건으로 고려하여 보다 실제에 가까운 상황에서 최소비용과 최대 생산율을 얻도록 프로그램을 개발하였다.

Predicting Cutting Forces in Face Milling with the Orthogonal Machining Theory (2차원 절삭이론을 이용한 정면밀링 절삭력 예측)

  • 김국원
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.19 no.12
    • /
    • pp.150-157
    • /
    • 2002
  • This paper presents an effective cutting force model that enable us to predict the instantaneous cutting force in face milling from a knowledge of the work material properties and cutting conditions. The development of the model is based on the orthogonal machining theory with the effective rake angle which is defined in the plane containing the cutting velocity and chip flow vectors. Face milling testes are performed at different feeds and, a fairly good agreement is shown between the predicted cutting forces and test results.

Modeling of the Specific Cutting Pressure to Predict the Cutting Force in Face Milling (정면 밀링 가공에서의 절삭력 예측을 위한 비절삭 저항 모델링)

  • Joo, Jung-Hoon;Kim, Kug-Weon
    • Proceedings of the KAIS Fall Conference
    • /
    • 2008.05a
    • /
    • pp.306-308
    • /
    • 2008
  • 본 논문은 정면 밀링 가공에서의 절삭력 예측을 위한 수학적 모델을 설정하고 컴퓨터 시뮬레이션을 수행하였다. 실험으로 얻은 절삭력 데이터를 이용하여 비절삭 저항을 모델링하였고 컴퓨터 시뮬레이션을 통해 절삭력을 예측하였다. 예측된 절삭력은 실제 실험을 통해 얻은 절삭력과 비교하여 본 모델의 타당성을 검증하였다.

  • PDF

Car-to-Car Offset Frontal Impact Modeling using Spring-Mass Model (Spring-Mass 모델을 이용한 차대차 부분정면충돌 모델링)

  • Lim, Jaemoon;Lee, Kwangwon
    • Journal of Auto-vehicle Safety Association
    • /
    • v.8 no.2
    • /
    • pp.11-16
    • /
    • 2016
  • The objective of this study was to construct the spring-mass models for the car-to-car offset frontal impact crash. The SISAME software was utilized to extract the spring-mass models using the data from the offset frontal crash test. The spring-mass model of the passenger car could effectively approximate the crash characteristics for the offset frontal barrier impact and the car-to-car offset frontal impact scenarios.

A Study on the Relative Distance in Taking Action to Avoid Ship`s Collision (선박충돌회피를 위한 피항개시거리에 관한 연구)

  • 김기윤
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.19 no.2
    • /
    • pp.99-105
    • /
    • 1983
  • In the Steering and Sailing Rules of International Regulations for Preventing Collicions at Sea, 1972, any relative distance between two vessels necessary for taking action to avoid collision in head-on situation is not referred. In this paper, the author analyzed the ship's collision avoiding actions from a viewpoint of ship motions and worked out mathematical formulas to calculate the relative distances necessary for collision avoiding actions. Figuring out the values of maneuvering indices through experiments of actual ships, the author applied these values to the calculationg formulas and calculated the minimum safe relative distances. On the assumption that two vessels same in size and condition are approaching each other in head-on situation, the minimum safe relative distance was calculated as 5.0 times, sufficient safe relative one as 10.0 times their own length.

  • PDF

An In-depth Analysis of Head-on Collision Accidents for Frontal Crash Tests of Automated Driving Vehicles (자율주행자동차 정면충돌평가방안 마련을 위한 국내 정면충돌사고 심층분석 연구)

  • Yohan Park;Wonpil Park;Seungki Kim
    • Journal of Auto-vehicle Safety Association
    • /
    • v.15 no.4
    • /
    • pp.88-94
    • /
    • 2023
  • The seating postures of passengers in the automated driving vehicle are possible in atypical forms such as rear-facing and lying down. It is necessary to improve devices such as airbags and seat belts to protect occupants from injury in accidents of the automated driving vehicle, and collision safety evaluation tests must be newly developed. The purpose of this study is to define representative types of head-on collision accidents to develop collision standards for autonomous vehicles that take into account changes in driving behavior and occupants' postures. 150 frontal collision cases remained by filtering (accident videos, images, AIS 2+, passenger car, etc…) and random sampling from approximately 320,000 accidents claimed by a major insurance company over the past 5 years. The most frequent accident type is a head-on collision between a vehicle going straight and a vehicle turning left from the opposite side, accounting for 54.7% of all accidents, and most of these accidents occur in permissive left turns. The next most common frontal collision is the center-lane violation by drowsy driving and careless driving, accounting for 21.3% of the total. For the two types above, data such as vehicle speed, contact point/area, and PDOF at the moment of impact are obtained through accident reconstruction using PC-Crash. As a result, two types of autonomous vehicle crash safety test scenarios are proposed: (1) a frontal oblique collision test based on the accident types between a straight vehicle and a left-turning vehicle, and (2) a small overlap collision test based on the head-on accidents of center-lane violation.