Related Experiment Video
Updated: Jul 3, 2025
07:18
Generating Lap Joints Via Friction Stir Spot Welding on DP780 Steel
Published on: August 13, 2019
7.0K
Fatigue properties of riveted joints under different hole perpendicularity errors and squeeze forces
Ming Li1, Wei Tian2, WenHe Liao2,3
1School of Mechanical Engineering, Nanjing Institute of Technology, Nanjing, People's Republic of China.
Microscopy Research and Technique
|February 13, 2024
Summary
Hole perpendicularity errors in riveted aircraft joints reduce fatigue life and increase interfacial gaps. However, increasing squeeze force can mitigate these negative effects, improving joint quality.
Area of Science:
- Mechanical Engineering
- Materials Science
- Aerospace Engineering
Background:
- Riveting is crucial for aircraft assembly, but hole perpendicularity errors during drilling and riveting impact joint quality.
- Understanding these errors is vital for ensuring the structural integrity and longevity of aerospace components.
Purpose of the Study:
- To experimentally investigate the effects of hole perpendicularity error and squeeze force on riveted joint performance.
- To analyze how tilt angle influences interference fit, contact states, microstructure, fatigue life, and fracture modes.
Main Methods:
- Experimental investigation of riveted joints subjected to varying hole tilt angles (0°, 2°, 4°) and squeeze forces.
- Analysis of interference fit size, interface contact, microstructure, fatigue life, and fracture morphology.
Main Results:
- Increased tilt angle leads to larger interference fit size and interfacial gaps.
- Fatigue life significantly decreases with increasing tilt angle, with a notable difference between 0° and 180° tilt directions.
- Higher squeeze force can partially offset the detrimental effects of tilt angle on fatigue life.
Conclusions:
- Hole perpendicularity error negatively impacts riveted joint fatigue life and introduces interfacial gaps.
- Squeeze force plays a critical role in mitigating the adverse effects of tilt angle and influences the failure mode.
Related Concept Videos
01:21Fatigue
181
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
181
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
267
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
267
01:18Stress Concentrations in Circular Shafts
175
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
175
01:22Fatigue Strength of Concrete
190
Fatigue, in the context of materials science and engineering, refers to the weakening or failure of a material caused by repeatedly applied loads, even if these loads are below the strength limit of the material. Fatigue strength in concrete is a critical property that influences its durability and longevity. Concrete can fail in two ways due to fatigue. Static fatigue or creep rupture occurs under a constant load or one that increases slowly. The other failure mode is due to cyclical or...
190
01:24Stress Concentrations
287
Stress concentration is when stress intensifies near discontinuities such as holes or abrupt cross-sectional changes in a structural member. This localized stress can often surpass the average stress within the member. The stress distribution in flat bars, either with a circular hole or varying widths connected by fillets, can be determined experimentally using a photoelastic method. The results are based on ratios of geometric parameters like the ratio of the hole's radius to the smaller...
287
01:18Saint-Venant's Principle
598
The principle of Saint-Venant postulates that the stress distribution within a structural member does not rely on the precise method of load application except in the vicinity of the load application points. Consider a scenario where loads are centrally applied on two plates. In this case, the plates move toward each other without any rotation. This movement causes the member to contract in length and expand in width and thickness. Uniform deformation across all elements and maintaining...
598