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Structural durability of automotive components is one of the key requirements in design and development of today’s automobiles. Virtual simulations are used to estimate component durability to save the cost and time required to build the components and testing. The objective of this work is to find the service life of automotive HVAC pipe assembly by calculating cumulative fatigue life for operation under actual powertrain load conditions. Modal transient response analysis is performed with the measured powertrain load time history. Strain based fatigue life analysis is carried out using modal superposition method (MSM). The estimated fatigue life was compared with the physical test results. This paper also explains the root cause of low fatigue life on pipe assembly and provide the solution.

The automotive door structure experience various static and dynamic loading conditions while going through an opening and closing operation. A typical swing door is attached to the body with two hinges and a check strap. These mechanisms carry the loads while the door is opened. Similarly, while closing the door, the latch/striker mechanism along with the seal around the periphery of the door react all loads. Typically, computer aided engineering (CAE) simulations are performed considering a nominal manufacturing (or build) tolerance condition, that results in one loading scenario. But while assembling the door with the body, the build variations in door mechanisms mentioned above can result in different loading scenarios and it should be accounted for design evaluation. This paper discusses various build tolerances and its effect on door durability performances to achieve a robust door design.

In vehicle development process, closures slam durability is one of the important measurement for body in white and closure design. In closure slam simulation event, the majority of dynamic forces absorbed through rubber seals and rubber bump-stops, which are typically mounted in-between the closure system and body in white (BIW). These auxiliary components also provide the cushioning to the structure and protect it from the panel interaction during abusive closure slam. In conventional computer aided engineering (CAE) simulation process, the stiffness of rubber bumpstop is often represented with linear stiffness data, which does not capture the rubber behavior for static and dynamic loading/unloading. Thus, it is necessary to develop the numerical material model for better rubber behavior simulation. This paper details the study of rubber bumpstop material behavior under static and dynamic loading/unloading using various material model approach.

In the vehicle development process, the door slam durability assessment is of significant importance in the estimation of fatigue life for body closure system. So far, various exertions have been taken into consideration to better represent the door slam simulation for door durability performance. Nowadays, with computer aided engineering (CAE) being extensively implemented, simulation procedures are constantly being investigated in order to get precise outcomes as physical testing. In a real world scenario, the customer closes the door frequently against the sealed cabin which offers the cabin pressure to close. The cabin pressure acts in the opposite direction of door closing providing the damping effect and minimizes the overall damage to the structure. Currently, simulations are focused on determining the total energy required for closing the door by summing up the energy lost in the weather seal and latch.

In a passenger car, suspension link bushings, engine and transmission mount bushings and bump-stops are made of elastomeric materials, to maximize the durability and comfort. Thus, deformation behavior of rubber and its durability is important for product design and development. In virtual engineering, simulating rubber fatigue is a complex exercise, since it needs right modeling strategy and coupon based testing material data. Principal stretches based Ogden model is used to characterize the hyper elastic deformation behavior of natural rubber. Fatigue crack growth approach used here for the fatigue analysis. Engine torque strut mount is used to control the engine and transmission fore aft motion and it is connected between body and Powertrain (PT) system. Powertrain events are predominant for damage contribution to mount failure. So, it is important to predict fatigue life of mount elastomer bushing under Powertrain loading.

An automotive wiring harness is the backbone of the electrical architecture, and it runs throughout the vehicle to transmit electric power. In a virtual simulation, the mechanical properties of individual strands cannot be considered for the harness bundle (or) cable. Predicting the mechanical properties of electrical cables is a challenging task, and it has major setbacks in virtual simulation. This paper proposes an approach to find out the mechanical properties of an electrical cable and explains how the values are used in virtual simulation. Cable modelling is represented as a lumped mass (or) modelled with a 1D element in the conventional FE modelling approach. In the first part of the study, finite element modelling and material modelling procedures of high and low-voltage electrical cables routed through brackets and troughs are discussed.

In automotive design space, door opening durability is one of the important design attribute to build a door structure. Customer often interact with door while ingress and egress a vehicle and that builds a perception of vehicle in customer’s mind. Now days, Computer Aided Engineering (CAE) is used extensively to simulate the real time door opening and closing event for designing the door structure for durability performance. Early prediction of durability performance and developing the countermeasures saves great amount of time and cost. This paper provides a brief study of detail checkstrap mechanism and its influence on door durability performance. Door checkstrap plays an important role in swing door design, it assists the door opening and closing with the help of check arm profile guided by roller and spring. This allows the load transferred from door to body through checkstrap first and then through hinges.

Design for Six Sigma (DFSS) is an essential tool and methodology for innovation projects to improve the product design/process and performance. This paper aims to present an application of the DFSS Taguchi Method for an automotive/vehicle component. High-Pressure Vacuum Assist Die Casting (HPVADC) technology is used to make Cast Aluminum Front Shock Tower. During the vehicle life, Shock Tower transfers the road high impact loads from the shock absorber to the body structure. Proving Ground (PG) and washout loads are often used to assess part strength, durability life and robustness. The initial design was not meeting the strength requirement for abusive washout loads. The project identified eight parameters (control factors) to study and to optimize the initial design. Simulation results confirmed that all eight selected control factors affect the part design and could be used to improve the Shock Tower's strength and performance.

Material modeling of Load floor made with Composite material is a challenging part in commercial finite element analysis (FEA) software. This paper presents the development of a material model for the prediction of composite properties. It specifically focuses on composites constructed with paper honeycomb as the core material and with glass fiber as the facing material. For automotive load floor applications, load deflection behavior is the most significant indicator of performance. The data accumulated from the testing of the core and facing materials individually is used to predict the load deflection behavior of a composite constructed structure. The prediction level of newly developed material modeling results are compared with physical test results of load floor from various vehicle platform. Also this paper describes the metamodel generation using the load floor simulation results for various load floor samples.